Thermoplastic Polymer Particles and Methods of Production and Uses Thereof

ABSTRACT

Thermoplastic polymer particles can be produced that comprise a thermoplastic polymer and an emulsion stabilizer (e.g., nanoparticles and/or surfactant) associated with an outer surface of the particles. The nanoparticles may be embedded in the outer surface of the particles. Melt emulsification can be used to produce said particles. For example, a method may include: mixing a mixture comprising a thermoplastic polymer, an carrier fluid that is immiscible with the thermoplastic polymer, and the emulsion stabilizer at a temperature greater than a melting point or softening temperature of the thermoplastic polymer and at a shear rate sufficiently high to disperse the thermoplastic polymer in the carrier fluid; cooling the mixture to below the melting point or softening temperature of the thermoplastic polymer to form the thermoplastic polymer particles; and separating the thermoplastic polymer particles from the carrier fluid.

PRIORITY CLAIM

The present application claims priority to U.S. Provisional PatentApplication No. 62/897,534.

TECHNICAL FIELD

The present disclosure relates to thermoplastic polymer particles andmethods of making such particles. Such particles, especially the highlyspherical thermoplastic polymer particles, may be useful, among otherthings, as starting material for additive manufacturing.

BACKGROUND

Three-dimensional (3-D) printing, also known as additive manufacturing,is a rapidly growing technology area. Although 3-D printing hastraditionally been used for rapid prototyping activities, this techniqueis being increasingly employed for producing commercial and industrialobjects, which may have entirely different structural and mechanicaltolerances than do rapid prototypes.

3-D printing operates by depositing either (a) small droplets or streamsof a melted or solidifiable material or (b) powder particulates inprecise deposition locations for subsequent consolidation into a largerobject, which may have any number of complex shapes. Such deposition andconsolidation processes typically occur under the control of a computerto afford layer-by-layer buildup of the larger object. In a particularexample, consolidation of powder particulates may take place in a 3-Dprinting system using a laser to promote selective laser sintering(SLS). Incomplete interlayer fusion may result in structural weakpoints, which may be problematic for printing objects having exactingstructural and mechanical tolerances.

Powder particulates usable in 3-D printing include thermoplasticpolymers, including thermoplastic elastomers, metals and othersolidifiable substances. Although a wide array of thermoplastic polymersare known, there are relatively few having properties suitable for usein 3-D printing, particularly when using powder bed fusion (PBF).Additive manufacturing methods using powdered materials include PBF,selective laser sintering (SLS), selective heat sintering (SHM),selective laser melting (SLM), electron beam melting (EBM), binderjetting, and multi jet fusion (MJF). In the SLS printing method, theparticles are fused together by the energy from a high-powered laser.Typical thermoplastic polymers suitable for use in 3-D printing includethose having sharp melting points and recrystallization points about 20°C. to 50° C. below the melting point. This difference may allow moreeffective coalescence between adjacent polymer layers to take place,thereby promoting improved structural and mechanical integrity.

For good printing performance to be realized using powder particulates,particularly polymer powder particulates, the powder particulates needto maintain good flow properties in the solid state. Flow properties maybe evaluated, for example, by measuring the fraction of powderparticulates from a sample that are able to pass through a standardsieve of a specified size and/or measuring of the angle of repose. Highfractions of sievable powder particulates may be indicative of theparticulates existing as non-agglomerated, substantially individualparticulates, which may be characteristic of ready powder flow. Lowervalues of the angle of repose, in contrast, may be characteristic ofready powder flow. A relatively narrow particle size distribution andregularity of the particulate shape in a sample may also aid inpromoting good powder flow performance.

Commercial powder particulates are oftentimes obtained by cryogenicgrinding or precipitation processes, which may result in irregularparticulate shapes and wide particle size distributions. Irregularparticulate shapes may result in poor powder flow performance during 3-Dprinting processes. In addition, powder particulates having shapeirregularity, especially those obtained from current commercialprocesses, may afford poor packing efficiency following deposition andconsolidation, thereby resulting in extensive void formation in aprinted object due to the powder particulates not packing closelytogether during deposition. Wide particle size distributions may besimilarly problematic in this regard. Although poor powder flowperformance may be addressed to some degree through dry blending withfillers and flow aids, these techniques may have limited effectivenesswith softer polymer materials, such as elastomers, due to particulateaggregation.

SUMMARY OF THE INVENTION

The present disclosure relates to thermoplastic polymer particles andmethods of making such particles. Such particles, especially the highlyspherical thermoplastic polymer particles, may be useful, among otherthings, as starting material for additive manufacturing.

Described herein is a composition comprising: particles comprising athermoplastic polymer and an emulsion stabilizer (e.g., nanoparticlesand/or surfactant) associated with an outer surface of the particles.

Described herein is a method comprising: mixing a mixture comprising athermoplastic polymer, an carrier fluid that is immiscible with thethermoplastic polymer, and emulsion stabilizer (e.g., nanoparticlesand/or surfactant) at a temperature greater than a melting point orsoftening temperature of the thermoplastic polymer and at a shear ratesufficiently high to disperse the thermoplastic polymer in the carrierfluid; cooling the mixture to below the melting point or softeningtemperature of the thermoplastic polymer to form solidified particlescomprising the thermoplastic polymer and the emulsion stabilizerassociated with an outer surface of the solidified particles; andseparating the solidified particles from the carrier fluid.

BRIEF DESCRIPTION OF THE DRAWINGS

The following figures are included to illustrate certain aspects of theembodiments, and should not be viewed as exclusive embodiments. Thesubject matter disclosed is capable of considerable modifications,alterations, combinations, and equivalents in form and function, as willoccur to those skilled in the art and having the benefit of thisdisclosure.

FIG. 1 is a flow chart of a nonlimiting example method 100 of thepresent disclosure.

FIG. 2 is a scanning electron micrograph of polyamide particles.

FIG. 3 is a scanning electron micrograph of polyamide particles.

FIG. 4 is a scanning electron micrograph of polyamide particles.

FIG. 5 is a scanning electron micrograph of polyamide particles.

FIG. 6 is a scanning electron micrograph of polyamide particles.

FIG. 7 is a scanning electron micrograph of polyamide particles.

FIG. 8 is a scanning electron micrograph of polyamide particles.

FIG. 9 is a scanning electron micrograph of polyamide particles.

FIG. 10 is a scanning electron micrograph of polyamide particles.

FIG. 11 is a scanning electron micrograph of polyamide particles.

FIG. 12 is a scanning electron micrograph of polyamide particles.

FIG. 13 is a scanning electron micrograph of polyamide particles.

FIG. 14 is a scanning electron micrograph of polyamide particles.

FIG. 15 is a scanning electron micrograph of polyamide particles.

FIG. 16 is a scanning electron micrograph of polyamide particles.

FIG. 17 is a scanning electron micrograph of polyamide particles.

FIG. 18 is a scanning electron micrograph of polyamide particles.

FIG. 19 is a scanning electron micrograph of polyamide particles.

FIG. 20 is a scanning electron micrograph of polyamide particles.

FIG. 21 is a scanning electron micrograph of polyamide particles.

FIG. 22 is a scanning electron micrograph of polyamide particles.

FIGS. 23A and 23B are scanning electron micrographs of polyamideparticles.

FIG. 24 is a scanning electron micrograph of polyamide particles.

FIGS. 25 and 26 are the volume density particle size distribution forthe particles screened and not screened, respectively.

FIG. 27 shows an illustrative optical microscopy image at 150×magnification of thermoplastic polyurethane particulates.

FIG. 28 shows an illustrative optical microscopy image of thermoplasticpolyurethane particulates.

FIGS. 29A and 29B show illustrative SEM images of thermoplasticpolyurethane particulates obtained in Comparative Example 2 at variousmagnifications.

FIG. 30 shows an illustrative optical microscopy image of thermoplasticpolyurethane particulates.

FIG. 31 shows an illustrative histogram of the particle sizes ofthermoplastic polyurethane particulates.

FIG. 32 shows an illustrative optical microscopy image of thermoplasticpolyurethane particulates.

FIG. 33 shows an illustrative histogram of the particle sizes ofthermoplastic polyurethane particulates.

FIG. 34 shows an illustrative optical microscopy image of thermoplasticpolyurethane particulates.

FIGS. 35A and 35B show illustrative SEM images of thermoplasticpolyurethane particulates at various magnifications.

FIG. 36 shows an illustrative histogram of the particle sizes ofthermoplastic polyurethane particulates.

FIG. 37 shows an illustrative optical microscopy image of thermoplasticpolyurethane particulates.

FIGS. 38A-38D show illustrative SEM images of thermoplastic polyurethaneparticulates at various magnifications.

FIG. 39 shows an illustrative histogram of the particle sizes ofthermoplastic polyurethane particulates.

FIG. 40 shows an illustrative optical microscopy image of thermoplasticpolyurethane particulates.

FIGS. 41A-41C show illustrative SEM images of thermoplastic polyurethaneparticulates at various magnifications.

FIG. 42 shows an illustrative histogram of the particle sizes ofthermoplastic polyurethane particulates.

FIGS. 43A-43E show illustrative SEM images of TPU 90A NAT thermoplasticpolyurethane particulates (ADVANC3D).

FIG. 44 shows an optical image of the printed product obtained from thethermoplastic polyurethane particulates.

FIG. 45 shows an illustrative optical microscopy image at 150×magnification of thermoplastic polyurethane particulates.

FIG. 46 shows an illustrative histogram of the particle sizes ofthermoplastic polyurethane particulates.

FIG. 47 shows an illustrative optical microscopy image at 150×magnification of thermoplastic polyurethane particulates.

FIGS. 48A and 48B show illustrative SEM images of thermoplasticpolyurethane particulates obtained in at various magnifications.

FIG. 49 shows an illustrative histogram of the particle sizes ofthermoplastic polyurethane particulates.

FIG. 50 shows an illustrative optical microscopy image at 100×magnification of thermoplastic polyurethane particulates obtained in.

FIG. 51 shows an illustrative histogram of the particle sizes ofthermoplastic polyurethane particulates.

FIG. 52 shows an illustrative optical microscopy image at 100×magnification of thermoplastic polyurethane particulates.

FIG. 53 shows an illustrative histogram of the particle sizes ofthermoplastic polyurethane particulates.

FIG. 54 shows an illustrative optical microscopy image at 300×magnification of thermoplastic polyurethane particulates.

FIG. 55 shows an illustrative histogram of the particle sizes ofthermoplastic polyurethane particulates.

FIG. 56 shows an illustrative optical microscopy image at 150×magnification of thermoplastic polyurethane particulates.

FIG. 57 shows an illustrative histogram of the particle sizes ofthermoplastic polyurethane particulates.

FIG. 58 shows an illustrative optical microscopy image at 150×magnification of thermoplastic polyurethane particulates.

FIG. 59 shows an illustrative histogram of the particle sizes ofthermoplastic polyurethane particulates.

FIG. 60 shows an illustrative optical microscopy image at 150×magnification of thermoplastic polyurethane particulates.

FIGS. 61A and 61B show illustrative SEM images of thermoplasticpolyurethane particulates at various magnifications.

FIG. 62 shows an illustrative histogram of the particle sizes ofthermoplastic polyurethane particulates.

FIG. 63 shows an illustrative optical microscopy image at 150×magnification of thermoplastic polyurethane particulates.

FIG. 64 shows an illustrative histogram of the particle sizes ofthermoplastic polyurethane particulates.

FIG. 65 shows an illustrative particle size distribution plot forthermoplastic polyurethane particulates.

FIG. 66 shows an optical image of the printed product.

DETAILED DESCRIPTION

The present disclosure relates to thermoplastic polymer particles andmethods of making such particles. Such particles, especially the highlyspherical thermoplastic polymer particles, may be useful, among otherthings, as starting material for additive manufacturing.

More specifically, the thermoplastic polymer particles described hereinare produced by melt emulsification methods where a thermoplasticpolymer is dispersed as a melt in a carrier fluid that is immisciblewith the thermoplastic polymer. A sufficient amount of shear is used tocause the thermoplastic polymer melt to form droplets in the carrierfluid. Emulsion stabilizers (e.g., nanoparticles and/or surfactants,including one or more members of each type in some cases) effect thesurface tension at the phase interface between the carrier fluid and thethermoplastic polymer melt. Once the melt emulsification process iscomplete, the dispersion is cooled, which solidifies the polymer intothermoplastic polymer particles.

Without being limited by theory, during the melt emulsification process,the emulsion stabilizers primarily reside at the interface between thepolymer melt and the carrier fluid. As a result, when the mixture iscooled, the emulsion stabilizers remain at said interface.Advantageously, the emulsion stabilizers at a surface of the resultantparticles may assist with the flow properties of the resultantparticles.

As described previously, traditional methods of forming thermoplasticpolymer particles with good flowability include at least two stepsincluding first forming (e.g., by cryogenic grinding or precipitationprocesses) and purifying the particles and second coating the particlesto some degree with a flow enhancing agent like nanoparticle silica,carbon black, or PTFE particles. The methods described hereinadvantageously produce thermoplastic polymer particles with a coatingthat enhances flowability of the particles in one process.

Further, without limitation by theory, the methods of the presentdisclosure appear to produce particles with a more homogeneous coverageof emulsion stabilizers, which may further improve flowability. Enhancedflowability is especially advantageous in additive manufacturingapplications like 3-D printing.

Definitions and Test Methods

As used herein, the term “immiscible” refers to a mixture of componentsthat, when combined, form two or more phases that have less than 5 wt %solubility in each other at ambient pressure and at room temperature orthe melting point of the component if it is solid at room temperature.For example, polyethylene oxide having 10,000 g/mol molecular weight isa solid at room temperature and has a melting point of 65° C. Therefore,said polyethylene oxide is immiscible with a material that is liquid atroom temperature if said material and said polyethylene oxide have lessthan 5 wt % solubility in each other at 65° C.

As used herein, the term “thermoplastic polymer” refers to a plasticpolymer material that softens and hardens reversibly on heating andcooling. Thermoplastic polymers encompass thermoplastic elastomers.

As used herein, the term “elastomer” refers to a copolymer comprising acrystalline “hard” section and an amorphous “soft” section. In the caseof a polyurethane, the crystalline section may include a portion of thepolyurethane comprising the urethane functionality and optional chainextender group, and the soft section may include the polyol, forinstance.

As used herein, the term “polyurethane” refers to a polymeric reactionproduct between a diisocyanate, a polyol, and an optional chainextender.

As used herein, the term “oxide” refers to both metal oxides andnon-metal oxides. For purposes of the present disclosure, silicon isconsidered to be a metal.

As used herein, the terms “associated,” “association,” and grammaticalvariations thereof between emulsion stabilizers and a surface refers tochemical bonding and/or physical adherence of the emulsion stabilizersto the surface. Without being limited by theory, it is believed that theassociations described herein between polymers and emulsion stabilizersare primarily physical adherences via hydrogen bonding and/or othermechanisms. However, chemical bonding may be occurring to some degree.

As used herein, the term “embed” relative to nanoparticles and a surfaceof a polymer particle refers to the nanoparticle being at leastpartially extending into the surface such that polymer is in contactwith the nanoparticle to a greater degree than would be if thenanoparticle were simply laid on the surface of the polymer particle.

Herein, D10, D50, D90, and diameter span are primarily used herein todescribe particle sizes. As used herein, the term “D10” refers to adiameter at with 10% of the sample (on a volume basis unless otherwisespecified) is comprised of particles having a diameter less than saiddiameter value. As used herein, the term “D50” refers to a diameter atwith 50% of the sample (on a volume basis unless otherwise specified) iscomprised of particles having a diameter less than said diameter value.As used herein, the term “D90” refers to a diameter at with 90% of thesample (on a volume basis unless otherwise specified) is comprised ofparticles having a diameter less than said diameter value.

As used herein, the terms “diameter span” and “span” and “span size”when referring to diameter provides an indication of the breadth of theparticle size distribution and is calculated as (D90−D10)/D50 (againeach D-value is based on volume, unless otherwise specified).

Particle size can be determined by light scattering techniques using aMalvern MASTERSIZER™ 3000 or analysis of optical digital micrographs.Unless otherwise specified, light scattering techniques are used foranalyzing particle size.

For light scattering techniques, the control samples were glass beadswith a diameter within the range of 15 μm to 150 μm under the tradenameQuality Audit Standards QAS4002™ obtained from Malvern Analytical Ltd.Samples were analyzed as dry powders, unless otherwise indicated. Theparticles analyzed were dispersed in air and analyzed using the AERO Sdry powder dispersion module with the MASTERSIZER™ 3000. The particlesizes were derived using instruments software from a plot of volumedensity as a function of size.

Particle size measurement and diameter span can also be determined byoptical digital microscopy. The optical images are obtained using aKeyence VHX-2000 digital microscope using version 2.3.5.1 software forparticle size analysis (system version 1.93).

As used herein, when referring to sieving, pore/screen sizes aredescribed per U.S.A. Standard Sieve (ASTM E11-17).

As used herein, the terms “circularity” and “sphericity” relative to theparticles refer to how close the particle is to a perfect sphere. Todetermine circularity, optical microscopy images are taken of theparticles. The perimeter (P) and area (A) of the particle in the planeof the microscopy image is calculated (e.g., using a SYSMEX FPIA 3000particle shape and particle size analyzer, available from MalvernInstruments). The circularity of the particle is C_(EA)/P, where C_(EA)is the circumference of a circle having the area equivalent to the area(A) of the actual particle.

As used herein, the term “sintering window” refers to the differencebetween the melting temperature (Tm) onset and the crystallizationtemperature (Tc) onset, or (Tm-Tc) onset. Tm, Tm (onset), Tc, and Tc(onset) are determined by differential scanning calorimetry per ASTME794-06(2018) with a 10° C./min ramp rate and a 10° C./min cool rate.

As used herein, the term “shear” refers to stirring or a similar processthat induces mechanical agitation in a fluid.

As used herein, the term “aspect ratio” refers to length divided bywidth, wherein the length is greater than the width.

The melting point of a polymer, unless otherwise specified, isdetermined by ASTM E794-06(2018) with 10° C./min ramping and coolingrates.

The softening temperature or softening point of a polymer, unlessotherwise specified, is determined by ASTM D6090-17. The softeningtemperature can be measured by using a cup and ball apparatus availablefrom Mettler-Toledo using a 0.50 gram sample with a heating rate of 1°C./min.

Angle of repose is a measure of the flowability of a powder. Angle ofrepose measurements were determined using a Hosokawa Micron PowderCharacteristics Tester PT-R using ASTM D6393-14 “Standard Test Methodfor Bulk Solids” Characterized by Carr Indices.”

Hausner ratio (H_(r)) is a measure of the flowability of a powder and iscalculated by H_(r)=ρ_(tap)/ρ_(bulk), where ρ_(bulk) is the bulk densityper ASTM D6393-14 and ρ_(tap) is the tapped density per ASTM D6393-14.

As used herein, the term “embed” relative to nanoparticles and a surfaceof a polymer particle refers to the nanoparticle being at leastpartially extending into the surface such that polymer is in contactwith the nanoparticle to a greater degree than would be if thenanoparticle were simply laid on the surface of the polymer particle.

As used herein, viscosity of carrier fluids are the kinematic viscosityat 25° C., unless otherwise specified, measured per ASTM D445-19. Forcommercially procured carrier fluids (e.g., PDMS oil), the kinematicviscosity data cited herein was provided by the manufacturer, whethermeasured according to the foregoing ASTM or another standard measurementtechnique.

Thermoplastic Polymer Particles and Methods of Making

FIG. 1 is a flow chart of a nonlimiting example method 100 of thepresent disclosure. The thermoplastic polymer 102, carrier fluid 104,and emulsion stabilizer 106 are combined 108 to produce a mixture 110.The components 102, 104, and 106 can be added in any order and includemixing and/or heating during the process of combining 108 the components102, 104, and 106.

The mixture 110 is then processed 112 by applying sufficiently highshear to the mixture 110 at a temperature greater than the melting pointor softening temperature of the thermoplastic polymer 102 to form a meltemulsion 114. Because the temperature is above the melting point orsoftening temperature of the thermoplastic polymer 102, thethermoplastic polymer 102 becomes a polymer melt. The shear rate shouldbe sufficient enough to disperse the polymer melt in the carrier fluid104 as droplets (i.e., the polymer emulsion 114). Without being limitedby theory, it is believed that, all other factors being the same,increasing shear should decrease the size of the droplets of the polymermelt in the carrier fluid 104. However, at some point there may bediminishing returns on increasing shear and decreasing droplet size ormay be disruptions to the droplet contents that decrease the quality ofparticles produced therefrom.

The melt emulsion 114 inside and/or outside the mixing vessel is thencooled 116 to solidify the polymer droplets into thermoplastic polymerparticles (also referred to as solidified thermoplastic polymerparticles). The cooled mixture 118 can then be treated 120 to isolatethe thermoplastic polymer particles 122 from other components 124 (e.g.,the carrier fluid 104, excess emulsion stabilizer 106, and the like) andwash or otherwise purify the thermoplastic polymer particles 122. Thethermoplastic polymer particles 122 comprise the thermoplastic polymer102 and at least a portion of the emulsion stabilizer 106 coating theouter surface of the thermoplastic polymer particles 122. Emulsionstabilizers 106, or a portion thereof, may be deposited as a uniformcoating on the thermoplastic polymer particles 122. In some instances,which may be dependent upon non-limiting factors such as the temperature(including cooling rate), the type of thermoplastic polymer 102, and thetypes and sizes of emulsion stabilizers 106, the nanoparticles ofemulsion stabilizers 106 may become at least partially embedded withinthe outer surface of thermoplastic polymer particles 122 in the courseof becoming associated therewith. Even without embedment taking place,at least the nanoparticles within emulsion stabilizers 106 may remainrobustly associated with thermoplastic polymer particles 122 tofacilitate their further use. In contrast, dry blending already formedthermoplastic polymer particulates (e.g., formed by cryogenic grindingor precipitation processes) with a flow aid like silica nanoparticlesdoes not result in a robust, uniform coating of the flow aid upon thethermoplastic polymer particulates.

Advantageously, carrier fluids and washing solvents of the systems andmethods described herein (e.g., method 101) can be recycled and reused.One skilled in the art will recognize any necessary cleaning of usedcarrier fluid and solvent necessary in the recycling process.

The thermoplastic polymer 102 and carrier fluid 104 should be chosensuch that at the various processing temperatures (e.g., from roomtemperature to process temperature) the thermoplastic polymer 102 andcarrier fluid 104 are immiscible. An additional factor that may beconsidered is the differences in (e.g., a difference or a ratio of)viscosity at process temperature between the molten polyamide 102 andthe carrier fluid 104. The differences in viscosity may affect dropletbreakup and particle size distribution. Without being limited by theory,it is believed that when the viscosities of the molten polyamide 102 andthe carrier fluid 104 are too similar, the circularity of the product asa whole may be reduced where the particles are more ovular and moreelongated structures are observed.

Examples of thermoplastic polymers 102 include, but are not limited to,polyamides, polyurethanes, polyethylenes, polypropylenes, polyacetals,polycarbonates, polybutylene terephthalate (PBT), polyethyleneterephthalate (PET), polyethylene naphthalate (PEN), polytrimethyleneterephthalate (PTT), polyhexamethylene terephthalate, polystyrenes,polyvinyl chlorides, polytetrafluoroethenes, polyesters (e.g.,polylactic acid), polyethers, polyether sulfones, polyetheretherketones, polyacrylates, polymethacrylates, polyimides, acrylonitrilebutadiene styrene (ABS), polyphenylene sulfides, vinyl polymers,polyarylene ethers, polyarylene sulfides, polysulfones, polyetherketones, polyamide-imides, polyetherimides, polyetheresters, copolymerscomprising a polyether block and a polyamide block (PEBA or polyetherblock amide), grafted or ungrafted thermoplastic polyolefins,functionalized or nonfunctionalized ethylene/vinyl monomer polymer,functionalized or nonfunctionalized ethylene/alkyl (meth)acrylates,functionalized or nonfunctionalized (meth)acrylic acid polymers,functionalized or nonfunctionalized ethylene/vinyl monomer/alkyl(meth)acrylate terpolymers, ethylene/vinyl monomer/carbonyl terpolymers,ethylene/alkyl (meth)acrylate/carbonyl terpolymers,methylmethacrylate-butadiene-styrene (MBS)-type core-shell polymers,polystyrene-block-polybutadiene-block-poly(methyl methacrylate) (SBM)block terpolymers, chlorinated or chlorosulphonated polyethylenes,polyvinylidene fluoride (PVDF), phenolic resins, poly(ethylene/vinylacetate)s, polybutadienes, polyisoprenes, styrenic block copolymers,polyacrylonitriles, silicones, and the like, and any combinationthereof. Copolymers comprising one or more of the foregoing may also beused in the methods and systems of the present disclosure.

The thermoplastic polymers 102 in the compositions and methods of thepresent disclosure may be elastomeric or non-elastomeric. Some of theforegoing examples of thermoplastic polymers 102 may be elastomeric ornon-elastomeric depending on the exact composition of the polymer. Forexample, polyethylene that is a copolymer of ethylene and propylene maybe elastomeric or not depending on the amount of propylene in thepolymer.

Thermoplastic elastomers generally fall within one of six classes:styrenic block copolymers, thermoplastic polyolefin elastomers,thermoplastic vulcanizates (also referred to as elastomeric alloys),thermoplastic polyurethanes, thermoplastic copolyesters, andthermoplastic polyamides (typically block copolymers comprisingpolyamide). Examples of thermoplastic elastomers can be found inHandbook of Thermoplastic Elastomers, 2nd ed., B. M. Walker and C. P.Rader, eds., Van Nostrand Reinhold, N.Y., 1988. Examples ofthermoplastic elastomers include, but are not limited to, elastomericpolyamides, polyurethanes, copolymers comprising a polyether block and apolyamide block (PEBA or polyether block amide), methylmethacrylate-butadiene-styrene (MBS)-type core-shell polymers,polystyrene-block-polybutadiene-block-poly(methyl methacrylate) (SBM)block terpolymers, polybutadienes, polyisoprenes, styrenic blockcopolymers, and polyacrylonitriles), silicones, and the like.Elastomeric styrenic block copolymers may include at least one blockselected from the group of: isoprene, isobutylene, butylene,ethylene/butylene, ethylene-propylene, and ethylene-ethylene/propylene.More specific elastomeric styrenic block copolymer examples include, butare not limited to, poly(styrene-ethylene/butylene),poly(styrene-ethylene/butylene-styrene),poly(styrene-ethylene/propylene), styrene-ethylene/propylene-styrene),poly(styrene-ethylene/propylene-styrene-ethylene-propylene),poly(styrene-butadiene-styrene),poly(styrene-butylene-butadiene-styrene), and the like, and anycombination thereof.

Examples of polyamides include, but are not limited to, polycaproamide(nylon 6, polyamide 6, or PA6), poly(hexamethylene succinamide) (nylon4,6, polyamide 4,6, or PA4,6), polyhexamethylene adipamide (nylon 6,6,polyamide 6,6, or PA6,6), polypentamethylene adipamide (nylon 5,6,polyamide 5,6, or PA5,6), polyhexamethylene sebacamide (nylon 6,10,polyamide 6,10, or PA6,10), polyundecaamide (nylon 11, polyamide 11, orPA11), polydodecaamide (nylon 12, polyamide 12, or PA12), andpolyhexamethylene terephthalamide (nylon 6T, polyamide 6T, or PA6T),nylon 10,10 (polyamide 10,10 or PA10,10), nylon 10,12 (polyamide 10,12or PA10,12), nylon 10,14 (polyamide 10,14 or PA10,14), nylon 10,18(polyamide 10,18 or PA10,18), nylon 6,18 (polyamide 6,18 or PA6,18),nylon 6,12 (polyamide 6,12 or PA6,12), nylon 6,14 (polyamide 6,14 orPA6,14), nylon 12,12 (polyamide 12,12 or PA12,12), and the like, and anycombination thereof. Copolyamides may also be used.

Examples of copolyamides include, but are not limited to, PA 11/10,10,PA 6/11, PA 6,6/6, PA 11/12, PA 10,10/10,12, PA 10,10/10,14, PA11/10,36, PA 11/6,36, PA 10,10/10,36, PA 6T/6,6, and the like, and anycombination thereof. A polyamide followed by a first number comma secondnumber is a polyamide having the first number of backbone carbonsbetween the nitrogens for the section having no pendent ═O and thesecond number of backbone carbons being between the two nitrogens forthe section having the pendent ═O. By way of nonlimiting example, nylon6,10 is [NH—(CH₂)₆—NH—CO—(CH₂)₈—CO]_(n). A polyamide followed bynumber(s) backslash number(s) are a copolymer of the polyamidesindicated by the numbers before and after the backslash.

Examples of polyurethanes include, but are not limited to, polyetherpolyurethanes, polyester polyurethanes, mixed polyether and polyesterpolyurethanes, and the like, and any combination thereof. Examples ofthermoplastic polyurethanes include, but are not limited to,poly[4,4′-methylenebis(phenylisocyanate)-alt-1,4-butanediol/di(propyleneglycol)/polycaprolactone], ELASTOLLAN® 1190A (a polyether polyurethaneelastomer, available from BASF), ELASTOLLAN® 1190A10 (a polyetherpolyurethane elastomer, available from BASF), and the like, and anycombination thereof.

Compatibilizers may optionally be used to improve the blendingefficiency and efficacy thermoplastic polyester with one or morethermoplastic polymers. Examples of polymer compatibilizers include, butnot limited to, PROPOLDER™ MPP2020 20 (polypropylene, available fromPolygroup Inc.), PROPOLDER™ MPP2040 40 (polypropylene, available fromPolygroup Inc.), NOVACOM™ HFS2100 (maleic anhydride functionalized highdensity polyethylene polymer, available from Polygroup Inc.), KEN-REACT™CAPS™ L™ 12/L (organometallic coupling agent, available from KenrichPetrochemicals), KEN-REACT™ CAPOW™ L™ 12/H (organometallic couplingagent, available from Kenrich Petrochemicals), KEN-REACT™ LICA™ 12(organometallic coupling agent, available from Kenrich Petrochemicals),KEN-REACT™ CAPS™ KPR™ 12/LV (organometallic coupling agent, availablefrom Kenrich Petrochemicals), KEN-REACT™ CAPOW™ KPR™ 12/H(organometallic coupling agent, available from Kenrich Petrochemicals),KEN-REACT™ titanates & zirconates (organometallic coupling agent,available from Kenrich Petrochemicals), VISTAMAXX™ (ethylene-propylenecopolymers, available from ExxonMobil), SANTOPRENE™ (thermoplasticvulcanizate of ethylene-propylene-diene rubber and polypropylene,available from ExxonMobil), VISTALON™ (ethylene-propylene-diene rubber,available from ExxonMobil), EXACT™ (plastomers, available fromExxonMobil) EXXELOR™ (polymer resin, available from ExxonMobil),FUSABOND™ M603 (random ethylene copolymer, available from Dow),FUSABOND™ E226 (anhydride modified polyethylene, available from Dow),BYNEL™ 41E710 (coextrudable adhesive resin, available from Dow), SURLYN™1650 (ionomer resin, available from Dow), FUSABOND™ P353 (a chemicallymodified polypropylene copolymer, available from Dow), ELVALOY™ PTW(ethylene terpolymer, available from Dow), ELVALOY™ 3427AC (a copolymerof ethylene and butyl acrylate, available from Dow), LOTADER™ AX8840(ethylene acrylate-based terpolymer, available from Arkema), LOTADER™3210 (ethylene acrylate-based terpolymer, available from Arkema),LOTADER™ 3410 (ethylene acrylate-based terpolymer, available fromArkema), LOTADER™ 3430 (ethylene acrylate-based terpolymer, availablefrom Arkema), LOTADER™ 4700 (ethylene acrylate-based terpolymer,available from Arkema), LOTADER™ AX8900 (ethylene acrylate-basedterpolymer, available from Arkema), LOTADER™ 4720 (ethyleneacrylate-based terpolymer, available from Arkema), BAXXODUR™ EC 301(amine for epoxy, available from BASF), BAXXODUR™ EC 311 (amine forepoxy, available from BASF), BAXXODUR™ EC 303 (amine for epoxy,available from BASF), BAXXODUR™ EC 280 (amine for epoxy, available fromBASF), BAXXODUR™ EC 201 (amine for epoxy, available from BASF),BAXXODUR™ EC 130 (amine for epoxy, available from BASF), BAXXODUR™ EC110 (amine for epoxy, available from BASF), styrenics, polypropylene,polyamides, polycarbonate, EASTMAN™ G-3003 (a maleic anhydride graftedpolypropylene, available from Eastman), RETAIN™ (polymer modifieravailable from Dow), AMPLIFY TY™ (maleic anhydride grafted polymer,available from Dow), INTUNE™ (olefin block copolymer, available fromDow), and the like and any combination thereof.

The thermoplastic polymers 102 may have a melting point or softeningtemperature of about 50° C. to about 450° C. (or about 50° C. to about125° C., or about 100° C. to about 175° C., or about 150° C. to about280° C., or about 200° C. to about 350° C., or about 300° C. to about450° C.).

The thermoplastic polymers 102 may have a glass transition temperature(ASTM E1356-08(2014) with 10° C./min ramping and cooling rates) of about−50° C. to about 400° C. (or about −50° C. to about 0° C., or about −25°C. to about 50° C., or about 0° C. to about 150° C., or about 100° C. toabout 250° C., or about 150° C. to about 300° C., or about 200° C. toabout 400° C.).

The thermoplastic polymers 102 may optionally comprise an additive.Typically, the additive would be present before addition of thethermoplastic polymers 102 to the mixture 110. Therefore, in thethermoplastic polymer melt droplets and resultant thermoplastic polymerparticles, the additive is dispersed throughout the thermoplasticpolymer. Accordingly, for clarity, this additive is referred to hereinas an “internal additive.” The internal additive may be blended with thethermoplastic polymer just prior to making the mixture 110 or well inadvance.

When describing component amounts in the compositions described herein(e.g., the mixture 110 and thermoplastic polymer particles 122), aweight percent based on the thermoplastic polymer 102 not inclusive ofthe internal additive. For example, a composition comprising 1 wt % ofemulsion stabilizer by weight of 100 g of a thermoplastic polymer 102comprising 10 wt % internal additive and 90 wt % thermoplastic polymeris a composition comprising 0.9 g of emulsion stabilizer, 90 g ofthermoplastic polymer, and 10 g of internal additive.

The internal additive may be present in the thermoplastic polymer 102 atabout 0.1 wt % to about 60 wt % (or about 0.1 wt % to about 5 wt %, orabout 1 wt % to about 10 wt %, or about 5 wt % to about 20 wt %, orabout 10 wt % to about 30 wt %, or about 25 wt % to about 50 wt %, orabout 40 wt % to about 60 wt %) of the thermoplastic polymer 102. Forexample, the thermoplastic polymer 102 may comprise about 70 wt % toabout 85 wt % of a thermoplastic polymer and about 15 wt % to about 30wt % of an internal additive like glass fiber or carbon fiber.

Examples of internal additives include, but are not limited to, fillers,strengtheners, pigments, pH regulators, and the like, and combinationsthereof. Examples of fillers include, but are not limited to, glassfibers, glass particles, mineral fibers, carbon fiber, oxide particles(e.g., titanium dioxide and zirconium dioxide), metal particles (e.g.,aluminum powder), and the like, and any combination thereof. Examples ofpigments include, but are not limited to, organic pigments, inorganicpigments, carbon black, and the like, and any combination thereof.

The thermoplastic polymer 102 may be present in the mixture 110 at about5 wt % to about 60 wt % (or about 5 wt % to about 25 wt %, or about 10wt % to about 30 wt %, or about 20 wt % to about 45 wt %, or about 25 wt% to about 50 wt %, or about 40 wt % to about 60 wt %) of thethermoplastic polymer 102 and carrier fluid 104 combined.

Suitable carrier fluids 104 have a viscosity at 25° C. of about 1,000cSt to about 150,000 cSt (or about 1,000 cSt to about 60,000 cSt, orabout 40,000 cSt to about 100,000 cSt, or about 75,000 cSt to about150,000 cSt).

Examples of carrier fluids 104 include, but are not limited to, siliconeoil, fluorinated silicone oils, perfluorinated silicone oils,polyethylene glycols, alkyl-terminal polyethylene glycols (e.g., C1-C4terminal alkyl groups like tetraethylene glycol dimethyl ether (TDG)),paraffins, liquid petroleum jelly, vison oils, turtle oils, soya beanoils, perhydrosqualene, sweet almond oils, calophyllum oils, palm oils,parleam oils, grapeseed oils, sesame oils, maize oils, rapeseed oils,sunflower oils, cottonseed oils, apricot oils, castor oils, avocadooils, jojoba oils, olive oils, cereal germ oils, esters of lanolic acid,esters of oleic acid, esters of lauric acid, esters of stearic acid,fatty esters, higher fatty acids, fatty alcohols, polysiloxanes modifiedwith fatty acids, polysiloxanes modified with fatty alcohols,polysiloxanes modified with polyoxy alkylenes, and the like, and anycombination thereof. Examples of silicone oils include, but are notlimited to, polydimethylsiloxane, methylphenylpolysiloxane, an alkylmodified polydimethylsiloxane, an alkyl modifiedmethylphenylpolysiloxane, an amino modified polydimethylsiloxane, anamino modified methylphenylpolysiloxane, a fluorine modifiedpolydimethylsiloxane, a fluorine modified methylphenylpolysiloxane, apolyether modified polydimethylsiloxane, a polyether modifiedmethylphenylpolysiloxane, and the like, and any combination thereof. Thecarrier fluid 104 may have one or more phases. For example,polysiloxanes modified with fatty acids and polysiloxanes modified withfatty alcohols (preferably with similar chain lengths for the fattyacids and fatty alcohols) may form a single-phase carrier fluid 104. Inanother example, a carrier fluid 104 comprising a silicone oil and analkyl-terminal polyethylene glycol may form a two-phase carrier fluid104.

The carrier fluid 104 may be present in the mixture 110 at about 40 wt %to about 95 wt % (or about 75 wt % to about 95 wt %, or about 70 wt % toabout 90 wt %, or about 55 wt % to about 80 wt %, or about 50 wt % toabout 75 wt %, or about 40 wt % to about 60 wt %) of the thermoplasticpolymer 102 and carrier fluid 104 combined.

In some instances, the carrier fluid 104 may have a density of about 0.6g/cm³ to about 1.5 g/cm³, and the thermoplastic polymer 102 has adensity of about 0.7 g/cm³ to about 1.7 g/cm³, wherein the thermoplasticpolymer has a density similar, lower, or higher than the density of thecarrier fluid.

The emulsion stabilizers used in the methods and compositions of thepresent disclosure may comprise nanoparticles (e.g. oxide nanoparticles,carbon black, polymer nanoparticles, and combinations thereof),surfactants, and the like, and any combination thereof.

Oxide nanoparticles may be metal oxide nanoparticles, non-metal oxidenanoparticles, or mixtures thereof. Examples of oxide nanoparticlesinclude, but are not limited to, silica, titania, zirconia, alumina,iron oxide, copper oxide, tin oxide, boron oxide, cerium oxide, thalliumoxide, tungsten oxide, and the like, and any combination thereof. Mixedmetal oxides and/or non-metal oxides, like aluminosilicates,borosilicates, and aluminoborosilicates, are also inclusive in the termmetal oxide. The oxide nanoparticles may by hydrophilic or hydrophobic,which may be native to the particle or a result of surface treatment ofthe particle. For example, a silica nanoparticle having a hydrophobicsurface treatment, like dimethyl silyl, trimethyl silyl, and the like,may be used in methods and compositions of the present disclosure.Additionally, silica with functional surface treatments likemethacrylate functionalities may be used in methods and compositions ofthe present disclosure. Unfunctionalized oxide nanoparticles may also besuitable for use as well.

Commercially available examples of silica nanoparticles include, but arenot limited to, AEROSIL® particles available from Evonik (e.g., AEROSIL®R812S (about 7 nm average diameter silica nanoparticles having ahydrophobically modified surface and a BET surface area of 260±30 m²/g),AEROSIL® RX50 (about 40 nm average diameter silica nanoparticles havinga hydrophobically modified surface and a BET surface area of 35±10m²/g), AEROSIL® 380 (silica nanoparticles having a hydrophilicallymodified surface and a BET surface area of 380±30 m²/g)), and the like,and any combination thereof.

Carbon black is another type of nanoparticle that may be present as anemulsion stabilizer in the compositions and methods disclosed herein.Various grades of carbon black will be familiar to one having ordinaryskill in the art, any of which may be used herein. Other nanoparticlescapable of absorbing infrared radiation may be used similarly.

Polymer nanoparticles are another type of nanoparticle that may bepresent as an emulsion stabilizer in the disclosure herein. Suitablepolymer nanoparticles may include one or more polymers that arethermosetting and/or crosslinked, such that they do not melt whenprocessed by melt emulsification according to the disclosure herein.High molecular weight thermoplastic polymers having high melting ordecomposition points may similarly comprise suitable polymernanoparticle emulsion stabilizers.

The nanoparticles may have an average diameter (D50 based on volume) ofabout 1 nm to about 500 nm (or about 10 nm to about 150 nm, or about 25nm to about 100 nm, or about 100 nm to about 250 nm, or about 250 nm toabout 500 nm).

The nanoparticles may have a BET surface area of about 10 m²/g to about500 m²/g (or about 10 m²/g to about 150 m²/g, or about 25 m²/g to about100 m²/g, or about 100 m²/g to about 250 m²/g, or about 250 m²/g toabout 500 m²/g).

Nanoparticles may be included in the mixture 110 at a concentration ofabout 0.01 wt % to about 10 wt % (or about 0.01 wt % to about 1 wt %, orabout 0.1 wt % to about 3 wt %, or about 1 wt % to about 5 wt %, orabout 5 wt % to about 10 wt %) based on the weight of the thermoplasticpolymer 102.

Surfactants may be anionic, cationic, nonionic, or zwitterionic.Examples of surfactants include, but are not limited to, sodium dodecylsulfate, sorbitan oleates,poly[dimethylsiloxane-co-[3-(2-(2-hydroxyethoxy)ethoxy)propylmethylsiloxane],docusate sodium (sodium1,4-bis(2-ethylhexoxy)-1,4-dioxobutane-2-sulfonate), and the like, andany combination thereof. Commercially available examples of surfactantsinclude, but are not limited to, CALFAX® DB-45 (sodium dodecyl diphenyloxide disulfonate, available from Pilot Chemicals), SPAN® 80 (sorbitanmaleate non-ionic surfactant), MERPOL® surfactants (available fromStepan Company), TERGITOL™ TMN-6 (a water-soluble, nonionic surfactant,available from DOW), TRITON™ X-100 (octyl phenol ethoxylate, availablefrom SigmaAldrich), IGEPAL® CA-520 (polyoxyethylene (5) isooctylphenylether, available from SigmaAldrich), BRIJ® S10 (polyethylene glycoloctadecyl ether, available from SigmaAldrich), and the like, and anycombination thereof.

Surfactants may be included in the mixture 110 at a concentration ofabout 0.01 wt % to about 10 wt % (or about 0.01 wt % to about 1 wt %, orabout 0.5 wt % to about 2 wt %, or about 1 wt % to about 3 wt %, orabout 2 wt % to about 5 wt %, or about 5 wt % to about 10 wt %) based onthe weight of the polyamide 102. Alternatively, the mixture 110 maycomprise no (or be absent of) surfactant.

A weight ratio of nanoparticles to surfactant may be about 1:10 to about10:1 (or about 1:10 to about 1:1, or about 1:5 to about 5:1, or about1:1 to about 10:1).

As described above, the components 102, 104, and 106 can be added in anyorder and include mixing and/or heating during the process of combining108 the components 102, 104, and 106. For example, the emulsionstabilizer 106 may first be dispersed in the carrier fluid 104,optionally with heating said dispersion, before adding the thermoplasticpolymer 102. In another nonlimiting example, the thermoplastic polymer102 may be heated to produce a polymer melt to which the carrier fluid104 and emulsion stabilizer 106 are added together or in either order.In yet another nonlimiting example, the thermoplastic polymer 102 andcarrier fluid 104 can be mixed at an a temperature greater than themelting point or softening temperature of the thermoplastic polymer 102and at a shear rate sufficient enough to disperse the thermoplasticpolymer melt in the carrier fluid 104. Then, the emulsion stabilizer 106can be added to form the mixture 110 and maintained at suitable processconditions for a set period of time.

Combining 108 the components 102, 104, and 106 in any combination canoccur in a mixing apparatus used for the processing 112 and/or anothersuitable vessel. By way of nonlimiting example, the thermoplasticpolymer 102 may be heated to a temperature greater than the meltingpoint or softening temperature of the thermoplastic polymer 102 in themixing apparatus used for the processing 112, and the emulsionstabilizer 106 may be dispersed in the carrier fluid 104 in anothervessel. Then, said dispersion may be added to the melt of thethermoplastic polymer 102 in the mixing apparatus used for theprocessing 112.

The mixing apparatuses used for the processing 112 to produce the meltemulsion 114 should be capable of maintaining the melt emulsion 114 at atemperature greater than the melting point or softening temperature ofthe thermoplastic polymer 102 and applying a shear rate sufficient todisperse the polymer melt in the carrier fluid 104 as droplets.

Examples of mixing apparatuses used for the processing 112 to producethe melt emulsion 114 include, but are not limited to, extruders (e.g.,continuous extruders, batch extruders, and the like), stirred reactors,blenders, reactors with inline homogenizer systems, and the like, andapparatuses derived therefrom.

Processing 112 and forming the melt emulsion 114 at suitable processconditions (e.g., temperature, shear rate, and the like) for a setperiod of time.

The temperature of processing 112 and forming the melt emulsion 114should be a temperature greater than the melting point or softeningtemperature of the thermoplastic polymer 102 and less than thedecomposition temperature of any components 102, 104, and 106 in themixture 110. For example, the temperature of processing 112 and formingthe melt emulsion 114 may be about 1° C. to about 50° C. (or about 1° C.to about 25° C., or about 5° C. to about 30° C., or about 20° C. toabout 50° C.) greater than the melting point or softening temperature ofthe thermoplastic polymer 102 provided the temperature of processing 112and forming the melt emulsion 114 is less than the decompositiontemperature of any components 102, 104, and 106 in the mixture 110.

The shear rate of processing 112 and forming the melt emulsion 114should be sufficiently high to disperse the polymer melt in the carrierfluid 104 as droplets. Said droplets should comprise droplets having adiameter of about 1000 μm or less (or about 1 μm to about 1000 μm, orabout 1 μm to about 50 μm, or about 10 μm to about 100 μm, or about 10μm to about 250 μm, or about 50 μm to about 500 μm, or about 250 μm toabout 750 μm, or about 500 μm to about 1000 μm).

The time for maintaining said temperature and shear rate for processing112 and forming the melt emulsion 114 may be 10 seconds to 18 hours orlonger (or 10 seconds to 30 minutes, or 5 minutes to 1 hour, or 15minutes to 2 hours, or 1 hour to 6 hours, or 3 hours to 18 hours).Without being limited by theory, it is believed that a steady state ofdroplet sizes will be reached at which point processing 112 can bestopped. That time may depend on, among other things, the temperature,shear rate, thermoplastic polymer 102 composition, the carrier fluid 104composition, and the emulsion stabilizer 106 composition.

The melt emulsion 114 may then be cooled 116. Cooling 116 can be slow(e.g., allowing the melt emulsion to cool under ambient conditions) tofast (e.g., quenching). For example, the rate of cooling may range fromabout 10° C./hour to about 100° C./second to almost instantaneous withquenching (for example in dry ice) (or about 10° C./hour to about 60°C./hour, or about 0.5° C./minute to about 20° C./minute, or about 1°C./minute to about 5° C./minute, or about 10° C./minute to about 60°C./minute, or about 0.5° C./second to about 10° C./second, or about 10°C./second to about 100° C./second).

During cooling, little to no shear may be applied to the melt emulsion114. In some instances, the shear applied during heating may be appliedduring cooling.

The cooled mixture 118 resulting from cooling 116 the melt emulsion 114comprises solidified thermoplastic polymer particles 122 (or simplythermoplastic polymer particles) and other components 124 (e.g., thecarrier fluid 104, excess emulsion stabilizer 106, and the like). Thethermoplastic polymer particles may be dispersed in the carrier fluid orsettled in the carrier fluid.

The cooled mixture 118 may then be treated 120 to the separatethermoplastic polymer particles 122 (or simply thermoplastic polymerparticles 122) from the other components 124. Suitable treatmentsinclude, but are not limited to, washing, filtering, centrifuging,decanting, and the like, and any combination thereof.

Solvents used for washing the thermoplastic polymer particles 122 shouldgenerally be (a) miscible with the carrier fluid 104 and (b) nonreactive(e.g., non-swelling and non-dissolving) with the thermoplastic polymer102. The choice of solvent will depend on, among other things, thecomposition of the carrier fluid and the composition of thethermoplastic polymer 102.

Examples of solvents include, but are not limited to, hydrocarbonsolvents (e.g., pentane, hexane, heptane, octane, cyclohexane,cyclopentane, decane, dodecane, tridecane, and tetradecane), aromatichydrocarbon solvents (e.g., benzene, toluene, xylene, 2-methylnaphthalene, and cresol), ether solvents (e.g., diethyl ether,tetrahydrofuran, diisopropyl ether, and dioxane), ketone solvents (e.g.,acetone and methyl ethyl ketone), alcohol solvents (e.g., methanol,ethanol, isopropanol, and n-propanol), ester solvents (e.g., ethylacetate, methyl acetate, butyl acetate, butyl propionate, and butylbutyrate), halogenated solvents (e.g., chloroform, bromoform,1,2-dichloromethane, 1,2-dichloroethane, carbon tetrachloride,chlorobenzene, and hexafluoroisopropanol), water, and the like, and anycombination thereof.

Solvent may be removed from the thermoplastic polymer particles 122 bydrying using an appropriate method such as air-drying, heat-drying,reduced pressure drying, freeze drying, or a hybrid thereof. The heatingmay be performed preferably at a temperature lower than the glasstransition point of the thermoplastic polymer (e.g., about 50° C. toabout 150° C.).

The thermoplastic polymer particles 122 after separation from the othercomponents 124 may optionally be further classified to produce purifiedthermoplastic polymer particles 128. For example, to narrow the particlesize distribution (or reduce the diameter span), the thermoplasticpolymer particles 122 can be passed through a sieve having a pore sizeof about 10 μm to about 250 μm (or about 10 μm to about 100 μm, or about50 μm to about 200 μm, or about 150 μm to about 250 μm).

In another example purification technique, the thermoplastic polymerparticles 122 may be washed with water to remove surfactant whilemaintaining substantially all of the nanoparticles associated with thesurface of the thermoplastic polymer particles 122. In yet anotherexample purification technique, the thermoplastic polymer particles 122may be blended with additives to achieve a desired final product. Forclarity, because such additives are blended with the thermoplasticparticles 122 or other particles resultant from the methods describedherein after the particles are solidified, such additives are referredto herein as “external additives.” Examples of external additivesinclude flow aids, other polymer particles, fillers, and the like, andany combination thereof.

In some instances, a surfactant used in making the thermoplastic polymerparticles 122 may be unwanted in downstream applications. Accordingly,yet another example purification technique may include at leastsubstantial removal of the surfactant from the thermoplastic polymerparticles 122 (e.g., by washing and/or pyrolysis).

The thermoplastic polymer particles 122 and/or purified thermoplasticpolymer particles 128 (referred to as particles 122/128) may becharacterized by composition, physical structure, and the like.

As described above, the emulsion stabilizers are at the interfacebetween the polymer melt and the carrier fluid. As a result, when themixture is cooled, the emulsion stabilizers remain at, or in thevicinity of, said interface. Therefore, the structure of the particles122/128 is, in general, includes emulsion stabilizers (a) dispersed onan outer surface of the particles 122/128 and/or (b) embedded in anouter portion (e.g., outer 1 vol %) of the particles 122/128.

Further, where voids form inside the polymer melt droplets, emulsionstabilizers 106 should generally be at (and/or embedded in) theinterface between the interior of the void and the thermoplasticpolymer. The voids generally do not contain the thermoplastic polymer.Rather, the voids may contain, for example, carrier fluid, air, or bevoid. The particles 122/128 may comprise carrier fluid at about 5 wt %or less (or about 0.001 wt % to about 5 wt %, or about 0.001 wt % toabout 0.1 wt %, or about 0.01 wt % to about 0.5 wt %, or about 0.1 wt %to about 2 wt %, or about 1 wt % to about 5 wt %) of the particles122/128.

The thermoplastic polymer 102 may be present in the particles 122/128 atabout 90 wt % to about 99.5 wt % (or about 90 wt % to about 95 wt %, orabout 92 wt % to about 97 wt %, or about 95 wt % to about 99.5 wt %) ofthe particles 122/128.

The emulsion stabilizers 106 may be present in the particles 122/128 atabout 10 wt % or less (or about 0.01 wt % to about 10 wt %, or about0.01 wt % to about 1 wt %, or about 0.5 wt % to about 5 wt %, or about 3wt % to about 7 wt %, or about 5 wt % to about 10 wt %) of the particles122/128. When purified to at least substantially remove surfactant oranother emulsion stabilizer, the emulsion stabilizers 106 may be presentin the particles 128 at less than 0.01 wt % (or 0 wt % to about 0.01 wt%, or 0 wt % to 0.001 wt %).

Upon forming thermoplastic particulates according to the disclosureherein, at least a portion of the nanoparticles, such as silicananoparticles, may be disposed as a coating upon the outer surface ofthe thermoplastic particulates. At least a portion of the surfactant, ifused, may be associated with the outer surface as well. The coating maybe disposed substantially uniformly upon the outer surface. As usedherein with respect to a coating, the term “substantially uniform”refers to even coating thickness in surface locations covered by thecoating composition (e.g., nanoparticles and/or surfactant),particularly the entirety of the outer surface. The emulsion stabilizers106 may form a coating that covers at least 5% (or about 5% to about100%, or about 5% to about 25%, or about 20% to about 50%, or about 40%to about 70%, or about 50% to about 80%, or about 60% to about 90%, orabout 70% to about 100%) of the surface area of the particles 122/128.When purified to at least substantially remove surfactant or anotheremulsion stabilizer, the emulsion stabilizers 106 may be present in theparticles 128 at less than 25% (or 0% to about 25%, or about 0.1% toabout 5%, or about 0.1% to about 1%, or about 1% to about 5%, or about1% to about 10%, or about 5% to about 15%, or about 10% to about 25%) ofthe surface area of the particles 128. The coverage of the emulsionstabilizers 106 on an outer surface of the particles 122/128 may bedetermined using image analysis of the SEM micrographs. The emulsionstabilizers 106 may form a coating that covers at least 5% (or about 5%to about 100%, or about 5% to about 25%, or about 20% to about 50%, orabout 40% to about 70%, or about 50% to about 80%, or about 60% to about90%, or about 70% to about 100%) of the surface area of the particles122/128. When purified to at least substantially remove surfactant oranother emulsion stabilizer, the emulsion stabilizers 106 may be presentin the particles 128 at less than 25% (or 0% to about 25%, or about 0.1%to about 5%, or about 0.1% to about 1%, or about 1% to about 5%, orabout 1% to about 10%, or about 5% to about 15%, or about 10% to about25%) of the surface area of the particles 128. The coverage of theemulsion stabilizers 106 on an outer surface of the particles 122/128may be determined using image analysis of the SEM micrographs

The particles 122/128 may have a D10 of about 0.1 μm to about 125 μm (orabout 0.1 μm to about 5 μm, about 1 μm to about 10 μm, about 5 μm toabout 30 μm, or about 1 μm to about 25 μm, or about 25 μm to about 75μm, or about 50 μm to about 85 μm, or about 75 μm to about 125 μm), aD50 of about 0.5 μm to about 200 μm (or about 0.5 μm to about 10 μm, orabout 5 μm to about 50 μm, or about 30 μm to about 100 μm, or about 30μm to about 70 μm, or about 25 μm to about 50 μm, or about 50 μm toabout 100 μm, or about 75 μm to about 150 μm, or about 100 μm to about200 μm), and a D90 of about 3 μm to about 300 μm (or about 3 μm to about15 μm, or about 10 μm to about 50 μm, or about 25 μm to about 75 μm, orabout 70 μm to about 200 μm, or about 60 μm to about 150 μm, or about150 μm to about 300 μm), wherein D10<D50<D90. The particles 122/128 mayalso have a diameter span of about 0.2 to about 10 (or about 0.2 toabout 0.5, or about 0.4 to about 0.8, or about 0.5 to about 1.0, orabout 1 to about 3, or about 2 to about 5, or about 5 to about 10).Without limitation, diameter span values of 1.0 or greater areconsidered broad, and diameter spans values of 0.75 or less areconsidered narrow. Without limitation, diameter span values of 1.0 orgreater are considered broad, and diameter spans values of 0.75 or lessare considered narrow.

In a first nonlimiting example, the particles 122/128 may have a D10 ofabout 0.1 μm to about 10 μm, a D50 of about 0.5 μm to about 25 μm, and aD90 of about 3 μm to about 50 μm, wherein D10<D50<D90. Said particles122/128 may have a diameter span of about 0.2 to about 2.

In a second nonlimiting example, the particles 122/128 may have a D10 ofabout 5 μm to about 30 μm, a D50 of about 30 μm to about 70 μm, and aD90 of about 70 μm to about 120 μm, wherein D10<D50<D90. Said particles122/128 may have a diameter span of about 1.0 to about 2.5.

In a third nonlimiting example, the particles 122/128 may have a D10 ofabout 25 μm to about 60 μm, a D50 of about 60 μm to about 110 μm, and aD90 of about 110 μm to about 175 μm, wherein D10<D50<D90. Said particles122/128 may have a diameter span of about 0.6 to about 1.5.

In a fourth nonlimiting example, the particles 122/128 may have a D10 ofabout 75 μm to about 125 μm, a D50 of about 100 μm to about 200 μm, anda D90 of about 125 μm to about 300 μm, wherein D10<D50<D90. Saidparticles 122/128 may have a diameter span of about 0.2 to about 1.2.

In a fifth nonlimiting example, the particles 122/128 may have a D10 ofabout 1 μm to about 50 μm (or about 5 μm to about 30 μm, or about 1 μmto about 25 μm, or about 25 μm to about 50 μm), a D50 of about 25 μm toabout 100 μm (or about 30 μm to about 100 μm, or about 30 μm to about 70μm, or about 25 μm to about 50 μm, or about 50 μm to about 100 μm), anda D90 of about 60 μm to about 300 μm (or about 70 μm to about 200 μm, orabout 60 μm to about 150 μm, or about 150 μm to about 300 μm), whereinD10<D50<D90. The particles 122/128 may also have a diameter span ofabout 0.4 to about 3 (or about 0.6 to about 2, or about 0.4 to about1.5, or about 1 to about 3).

The particles 122/128 may have a circularity of about 0.7 or greater (orabout 0.7 to about 0.95, or about 0.9 to about 1.0, or about 0.93 toabout 0.99, or about 0.95 to about 0.99, or about 0.97 to about 0.99, orabout 0.98 to 1.0).

The particles 122/128 may have an angle of repose of about 20° to about45° (or about 25° to about 35°, or about 30° to about 40°, or about 35°to about 45°).

The particles 122/128 may have a Hausner ratio of about 1.0 to about 1.5(or about 1.0 to about 1.2, or about 1.1 to about 1.3, or about 1.2 toabout 1.35, or about 1.3 to about 1.5).

The particles 122/128 may have a bulk density of about 0.3 g/cm³ toabout 0.8 g/cm³ (or about 0.3 g/cm³ to about 0.6 g/cm³, or about 0.4g/cm³ to about 0.7 g/cm³, or about 0.5 g/cm³ to about 0.6 g/cm³, orabout 0.5 g/cm³ to about 0.8 g/cm³).

Depending on the temperature and shear rate of processing 112 and thecomposition and relative concentrations of the components 102, 104, and106, different shapes of the structures that compose the particles122/128 have been observed. Typically, the particles 122/128 comprisesubstantially spherical particles (having a circularity of about 0.97 orgreater). However, other structures included disc and elongatedstructures have been observed in the particles 122/128. Therefore, theparticles 122/128 may comprise one or more of: (a) substantiallyspherical particles having a circularity of 0.97 or greater, (b) discstructures having an aspect ratio of about 2 to about 10, and (c)elongated structures having an aspect ratio of 10 or greater. Each ofthe (a), (b), and (c) structures have emulsion stabilizers dispersed onan outer surface of the (a), (b), and (c) structures and/or embedded inan outer portion of the (a), (b), and (c) structures. At least some ofthe (a), (b), and (c) structures may be agglomerated. For example, the(c) elongated structures may be laying on the surface of the (a)substantially spherical particles.

The particles 122/128 may have a sintering window that is within 10° C.,preferably within 5° C., of the sintering window of the thermoplasticpolymer 102 (comprising one or more PP-polyamides and optionally one ormore other thermoplastic polymers).

Applications of Thermoplastic Polymer Particles

The thermoplastic polymer particles described herein may be utilized in3-D print processes, particularly those employing selective lasersintering to promote particulate consolidation. The thermoplasticpolymer particles of the present disclosure may exhibit advantageousproperties over polymer particulates having irregular shapes or widerparticulate distributions, such as those available commercially. Innonlimiting examples, the thermoplastic polymer particles of the presentdisclosure may undergo consolidation at lower laser powers and afford adecreased extent of void formation in an object produced by 3-Dprinting.

3-D printing processes of the present disclosure may comprise:depositing thermoplastic polymer particles of the present disclosureupon a surface in a specified shape, and once deposited, heating atleast a portion of the thermoplastic polymer particles to promoteconsolidation thereof and form a consolidated body (object), such thatthe consolidated body has a void percentage of about 1% or less afterbeing consolidated. For example, heating and consolidation of thethermoplastic polymer particles may take place in a 3-D printingapparatus employing a laser, such that heating and consolidation takeplace by selective laser sintering.

Any of the thermoplastic polymer particles disclosed herein may beformulated in a composition suitable for 3-D printing. Choice of thecomposition and type of elastomeric particulate may be based uponvarious factors such as, but not limited to, the laser power used forselective laser sinter, the type of object being produced, and theintended use conditions for the object.

Examples of objects that may be 3-D printed using the thermoplasticpolymer particles of the present disclosure include, but are not limitedto, containers (e.g., for food, beverages, cosmetics, personal carecompositions, medicine, and the like), shoe soles, toys, furniture partsand decorative home goods, plastic gears, screws, nuts, bolts, cableties, automotive parts, medical items, prosthetics, orthopedic implants,aerospace/aircraft-related parts, production of artifacts that aidlearning in education, 3D anatomy models to aid in surgeries, robotics,biomedical devices (orthotics), home appliances, dentistry, electronics,sporting goods, and the like.

Other applications for the thermoplastic particulates of the presentdisclosure may include, but are not limited to, use as a filler inpaints and powder coatings, inkjet materials and electrophotographictoners, and the like. In some instances, the thermoplastic particulatesmay have other preferred characteristics like diameter and span to beuseful in said other applications.

Nonlimiting Example Embodiments

A first nonlimiting embodiment of the present disclosure is acomposition comprising: particles comprising a thermoplastic polymer(e.g., thermoplastic elastomer) and an emulsion stabilizer (e.g.,nanoparticles and/or surfactant) associated with an outer surface of theparticles. The first nonlimiting embodiment may include one or more ofthe following: Element 1: wherein the emulsion stabilizer comprisesnanoparticles and at least some of the nanoparticles are embedded in theouter surface of the particles; Element 2: wherein the thermoplasticpolymer is present at 90 wt % to 99.5 wt % of the particle; Element 3:wherein at least some of the particles have a void comprising theemulsion stabilizer at a void/thermoplastic polymer interface; Element4: Element 3 and wherein the emulsion stabilizer comprises nanoparticlesand the nanoparticles are embedded in the void/thermoplastic polymerinterface; Element 5: Element 3 and wherein the void contains a carrierfluid having a viscosity at 25° C. of 1,000 cSt to 150,000 cSt; Element6: wherein the particles further comprises elongated structures on thesurface of the particles, wherein the elongated structures comprises thethermoplastic polymer with the emulsion stabilizer associated with anouter surface of the elongated structures; Element 7: wherein theemulsion stabilizer forms a coating that covers less than 5% of thesurface of the particles; Element 8: wherein the emulsion stabilizerforms a coating that covers at least 5% of the surface of the particles;Element 9: wherein the emulsion stabilizer forms a coating that coversat least 25% of the surface of the particles; Element 10: wherein theemulsion stabilizer forms a coating that covers at least 50% of thesurface of the particles; Element 11: wherein the particles furthercomprise a carrier fluid having a viscosity at 25° C. of 1,000 cSt to150,000 cSt; Element 12: wherein the carrier fluid is present at about 5wt % or less of the particles; Element 13: wherein the nanoparticleshave an average diameter of 1 nm to 500 nm; Element 14: wherein thenanoparticles have a BET surface area of 10 m²/g to 500 m²/g; Element15: wherein the thermoplastic polymer is selected from the groupconsisting of: polyamides, polyurethanes, polyethylenes, polypropylenes,polyacetals, polycarbonates, polybutylene terephthalate (PBT),polyethylene terephthalate (PET), polyethylene naphthalate (PEN),polytrimethylene terephthalate (PTT), polyhexamethylene terephthalate,polystyrenes, polyvinyl chlorides, polytetrafluoroethenes, polyesters(e.g., polylactic acid), polyethers, polyether sulfones, polyetheretherketones, polyacrylates, polymethacrylates, polyimides, acrylonitrilebutadiene styrene (ABS), polyphenylene sulfides, vinyl polymers,polyarylene ethers, polyarylene sulfides, polysulfones, polyetherketones, polyamide-imides, polyetherimides, polyetheresters, copolymerscomprising a polyether block and a polyamide block (PEBA or polyetherblock amide), grafted or ungrafted thermoplastic polyolefins,functionalized or nonfunctionalized ethylene/vinyl monomer polymer,functionalized or nonfunctionalized ethylene/alkyl (meth)acrylates,functionalized or nonfunctionalized (meth)acrylic acid polymers,functionalized or nonfunctionalized ethylene/vinyl monomer/alkyl(meth)acrylate terpolymers, ethylene/vinyl monomer/carbonyl terpolymers,ethylene/alkyl (meth)acrylate/carbonyl terpolymers,methylmethacrylate-butadiene-styrene (MBS)-type core-shell polymers,polystyrene-block-polybutadiene-block-poly(methyl methacrylate) (SBM)block terpolymers, chlorinated or chlorosulphonated polyethylenes,polyvinylidene fluoride (PVDF), phenolic resins, poly(ethylene/vinylacetate)s, polybutadienes, polyisoprenes, styrenic block copolymers,polyacrylonitriles, silicones, and any combination thereof; Element 16:wherein a melting point or softening temperature of the thermoplasticpolymer is 50° C. to 450° C.; Element 17: wherein the particles have aD10 of about 0.5 μm to about 125 μm, a D50 of about 1 μm to about 200μm, and a D90 of about 70 μm to about 300 μm, wherein D10<D50<D90;Element 18: wherein the particles have a diameter span of about 0.2 toabout 10; Element 19: wherein the particles have a D10 of about 5 μm toabout 30 μm, a D50 of about 30 μm to about 70 μm, and a D90 of about 70μm to about 120 μm, wherein D10<D50<D90; Element 20: Element 19 andwherein the particles have a diameter span of about 1.0 to about 2.5;Element 21: wherein the particles have a D10 of about 25 μm to about 60μm, a D50 of about 60 μm to about 110 μm, and a D90 of about 110 μm toabout 175 μm, wherein D10<D50<D90; Element 22: Element 21 and whereinthe particles have a diameter span of about 0.6 to about 1.5; Element23: wherein the particles have a D10 of about 75 μm to about 125 μm, aD50 of about 100 μm to about 200 μm, and a D90 of about 125 μm to about300 μm, wherein D10<D50<D90; Element 24: Element 23 and wherein thesolidified particles have a diameter span of about 0.2 to about 1;Element 25: wherein the particles have a circularity of about 0.90 toabout 1.0; and Element 26: wherein the particles have a Hausner ratio ofabout 1.0 to about 1.5. Examples of combinations include, but are notlimited to, Element 1 in combination with one or more of Elements 2-26;Element 3 (optionally in combination with Element 4 and/or Element 5) incombination with one or more of Elements 2 and 4-26; and two or more ofElements 1-15 in combination.

A second nonlimiting embodiment of the present disclosure is a methodcomprising: mixing a mixture comprising a thermoplastic polymer, ancarrier fluid that is immiscible with the thermoplastic polymer (e.g.,thermoplastic elastomer), and emulsion stabilizer (e.g., nanoparticlesand/or surfactant) at a temperature greater than a melting point orsoftening temperature of the thermoplastic polymer and at a shear ratesufficiently high to disperse the thermoplastic polymer in the carrierfluid; cooling the mixture to below the melting point or softeningtemperature of the thermoplastic polymer to form solidified particlescomprising the thermoplastic polymer and the emulsion stabilizerassociated with an outer surface of the solidified particles; andseparating the solidified particles from the carrier fluid. The firstnonlimiting embodiment may include one or more of the following: Element1; Element 2; Element 3; Element 4; Element 5; Element 6; Element 7;Element 8; Element 9; Element 10; Element 11; Element 12; Element 13;Element 14; Element 15; Element 16; Element 17; Element 18; Element 19;Element 20; Element 21; Element 22; Element 23; Element 24; Element 25;Element 26; Element 27: wherein the thermoplastic polymer is present inthe mixture at 5 wt % to 60 wt % of the mixture; Element 28: wherein theemulsion stabilizer is present in the mixture at 0.05 wt % to 5 wt % byweight of the thermoplastic polymer; Element 29: wherein the carrierfluid is selected from the group consisting of: silicone oil,fluorinated silicone oils, perfluorinated silicone oils, polyethyleneglycols, alkyl-terminal polyethylene glycols, paraffins, liquidpetroleum jelly, vison oils, turtle oils, soya bean oils,perhydrosqualene, sweet almond oils, calophyllum oils, palm oils,parleam oils, grapeseed oils, sesame oils, maize oils, rapeseed oils,sunflower oils, cottonseed oils, apricot oils, castor oils, avocadooils, jojoba oils, olive oils, cereal germ oils, esters of lanolic acid,esters of oleic acid, esters of lauric acid, esters of stearic acid,fatty esters, higher fatty acids, fatty alcohols, polysiloxanes modifiedwith fatty acids, polysiloxanes modified with fatty alcohols,polysiloxanes modified with polyoxy alkylenes, and any combinationthereof; Element 30: Element 29 and wherein the silicone oil is selectedfrom the group consisting of: polydimethylsiloxane,methylphenylpolysiloxane, an alkyl modified polydimethylsiloxane, analkyl modified methylphenylpolysiloxane, an amino modifiedpolydimethylsiloxane, an amino modified methylphenylpolysiloxane, afluorine modified polydimethylsiloxane, a fluorine modifiedmethylphenylpolysiloxane, a polyether modified polydimethylsiloxane, apolyether modified methylphenylpolysiloxane, and any combinationthereof; Element 31: wherein the carrier fluid has a density of 0.6g/cm³ to 1.5 g/cm³, wherein the thermoplastic polymer has a density of0.7 g/cm³ to 1.7 g/cm³; Element 32: wherein mixing occurs in an extrude;Element 33: wherein mixing occurs in a stirred reactor; and Element 33:wherein the mixture further comprises a surfactant. Example ofcombinations include, but are not limited to: those described relativeto the first nonlimiting embodiment; Element 1 in combination with oneor more of Elements 27-33; Element 3 (and optionally Element 4 and/orElement 5) in combination with one or more of Elements 27-33; two ormore of Elements 27-33 in combination; and one or more of Elements 27-33in combination with one or more of Elements 1-26.

Clauses

Clause 1. A composition comprising: particles comprising a thermoplasticpolymer (e.g., thermoplastic elastomer) and an emulsion stabilizer(e.g., nanoparticles and/or surfactant) associated with an outer surfaceof the particles.

Clause 2. The composition of Clause 1, wherein the emulsion stabilizercomprises nanoparticles and at least some of the nanoparticles areembedded in the outer surface of the particles.

Clause 3. The composition of Clause 1, wherein the thermoplastic polymeris present at 90 wt % to 99.5 wt % of the particle.

Clause 4. The composition of Clause 1, wherein at least some of theparticles have a void comprising the emulsion stabilizer at avoid/thermoplastic polymer interface.

Clause 5. The composition of Clause 4, wherein the emulsion stabilizercomprises nanoparticles and the nanoparticles are embedded in thevoid/thermoplastic polymer interface.

Clause 6. The composition of Clause 4, wherein the void contains acarrier fluid having a viscosity at 25° C. of 1,000 cSt to 150,000 cSt

Clause 7. The composition of Clause 1, wherein the particles furthercomprises elongated structures on the surface of the particles, whereinthe elongated structures comprises the thermoplastic polymer with theemulsion stabilizer associated with an outer surface of the elongatedstructures.

Clause 8. The composition of Clause 1, wherein the emulsion stabilizerforms a coating that covers less than 5% of the surface of theparticles.

Clause 9. The composition of Clause 1, wherein the emulsion stabilizerforms a coating that covers at least 5% of the surface of the particles.

Clause 10. The composition of Clause 1, wherein the emulsion stabilizerforms a coating that covers at least 25% of the surface of theparticles.

Clause 11. The composition of Clause 1, wherein the emulsion stabilizerforms a coating that covers at least 50% of the surface of theparticles.

Clause 12. The composition of Clause 1, wherein the particles furthercomprise a carrier fluid having a viscosity at 25° C. of 1,000 cSt to150,000 cSt.

Clause 13. The composition of Clause 12, wherein the carrier fluid ispresent at about 5 wt % or less of the particles.

Clause 14. The composition of Clause 1, wherein the nanoparticles havean average diameter of 1 nm to 500 nm.

Clause 15. The method of Clause 1, wherein the nanoparticles have a BETsurface area of 10 m²/g to 500 m²/g.

Clause 16. The composition of Clause 1, wherein the thermoplasticpolymer is selected from the group consisting of: polyamides,polyurethanes, polyethylenes, polypropylenes, polyacetals,polycarbonates, polybutylene terephthalate (PBT), polyethyleneterephthalate (PET), polyethylene naphthalate (PEN), polytrimethyleneterephthalate (PTT), polyhexamethylene terephthalate, polystyrenes,polyvinyl chlorides, polytetrafluoroethenes, polyesters (e.g.,polylactic acid), polyethers, polyether sulfones, polyetheretherketones, polyacrylates, polymethacrylates, polyimides, acrylonitrilebutadiene styrene (ABS), polyphenylene sulfides, vinyl polymers,polyarylene ethers, polyarylene sulfides, polysulfones, polyetherketones, polyamide-imides, polyetherimides, polyetheresters, copolymerscomprising a polyether block and a polyamide block (PEBA or polyetherblock amide), grafted or ungrafted thermoplastic polyolefins,functionalized or nonfunctionalized ethylene/vinyl monomer polymer,functionalized or nonfunctionalized ethylene/alkyl (meth)acrylates,functionalized or nonfunctionalized (meth)acrylic acid polymers,functionalized or nonfunctionalized ethylene/vinyl monomer/alkyl(meth)acrylate terpolymers, ethylene/vinyl monomer/carbonyl terpolymers,ethylene/alkyl (meth)acrylate/carbonyl terpolymers,methylmethacrylate-butadiene-styrene (MBS)-type core-shell polymers,polystyrene-block-polybutadiene-block-poly(methyl methacrylate) (SBM)block terpolymers, chlorinated or chlorosulphonated polyethylenes,polyvinylidene fluoride (PVDF), phenolic resins, poly(ethylene/vinylacetate)s, polybutadienes, polyisoprenes, styrenic block copolymers,polyacrylonitriles, silicones, and any combination thereof.

Clause 17. The composition of Clause 1, wherein a melting point orsoftening temperature of the thermoplastic polymer is 50° C. to 450° C.

Clause 18. The composition of Clause 1, wherein the particles have a D10of about 0.5 μm to about 125 μm, a D50 of about 1 μm to about 200 μm,and a D90 of about 70 μm to about 300 μm, wherein D10<D50<D90.

Clause 19. The composition of Clause 1, wherein the particles have adiameter span of about 0.2 to about 10.

Clause 20. The composition of Clause 1, wherein the particles have a D10of about 5 μm to about 30 μm, a D50 of about 30 μm to about 70 μm, and aD90 of about 70 μm to about 120 μm, wherein D10<D50<D90.

Clause 21. The composition of Clause 20, wherein the particles have adiameter span of about 1.0 to about 2.5.

Clause 22. The composition of Clause 1, wherein the particles have a D10of about 25 μm to about 60 μm, a D50 of about 60 μm to about 110 μm, anda D90 of about 110 μm to about 175 μm, wherein D10<D50<D90.

Clause 23. The composition of Clause 22, wherein the particles have adiameter span of about 0.6 to about 1.5.

Clause 24. The composition of Clause 1, wherein the particles have a D10of about 75 μm to about 125 μm, a D50 of about 100 μm to about 200 μm,and a D90 of about 125 μm to about 300 μm, wherein D10<D50<D90.

Clause 25. The composition of Clause 24, wherein the solidifiedparticles have a diameter span of about 0.2 to about 1.2.

Clause 26. The composition of Clause 1, wherein the particles have acircularity of about 0.90 to about 1.0.

Clause 27. The composition of Clause 1, wherein the particles have aHausner ratio of about 1.0 to about 1.5.

Clause 28. The composition of Clause 1, wherein the nanoparticlescomprise oxide nanoparticles.

Clause 29. The composition of Clause 1, wherein the nanoparticlescomprise carbon black.

Clause 30. The composition of Clause 1, wherein the nanoparticlescomprise polymer nanoparticles.

Clause 31. The composition of Clause 1, wherein the thermoplasticpolymer comprises a thermoplastic elastomer.

Clause 32. The composition of Clause 1, wherein the thermoplasticpolymer is a thermoplastic elastomer.

Clause 33. A method comprising: mixing a mixture comprising athermoplastic polymer (e.g., thermoplastic elastomer), an carrier fluidthat is immiscible with the thermoplastic polymer, and an emulsionstabilizer at a temperature greater than a melting point or softeningtemperature of the thermoplastic polymer and at a shear ratesufficiently high to disperse the thermoplastic polymer in the carrierfluid; cooling the mixture to below the melting point or softeningtemperature of the thermoplastic polymer to form solidified particlescomprising the thermoplastic polymer and the emulsion stabilizerassociated with an outer surface of the solidified particles; andseparating the solidified particles from the carrier fluid.

Clause 34. The method of Clause 33, wherein the emulsion stabilizercomprises nanoparticles at least some of the nanoparticles are embeddedin the outer surface of the solidified particles.

Clause 35. The method of Clause 33, wherein at least some of thesolidified particles have a void comprising the emulsion stabilizer at avoid/thermoplastic polymer interface.

Clause 36. The method of Clause 35, wherein the emulsion stabilizercomprises nanoparticles and the nanoparticles are embedded in thevoid/thermoplastic polymer interface.

Clause 37. The method of claim Clause 35, wherein the void contains thecarrier fluid.

Clause 38. The composition of Clause 33, wherein the solidifiedparticles further comprises elongated structures on the surface of thesolidified particles, wherein the elongated structures comprises thethermoplastic polymer with the emulsion stabilizer associated with anouter surface of the elongated structures.

Clause 39. The composition of Clause 33, wherein the emulsion stabilizerforms a coating that covers less than 5% of the surface of thesolidified particles.

Clause 40. The composition of Clause 33, wherein the emulsion stabilizerforms a coating that covers at least 5% of the surface of the solidifiedparticles.

Clause 41. The composition of Clause 33, wherein the emulsion stabilizerforms a coating that covers at least 25% of the surface of thesolidified particles.

Clause 42. The composition of Clause 33, wherein the emulsion stabilizerforms a coating that covers at least 50% of the surface of thesolidified particles.

Clause 43. The method of Clause 33, wherein the thermoplastic polymer ispresent in the mixture at 5 wt % to 60 wt % of the mixture.

Clause 44. The method of Clause 33, wherein the emulsion stabilizer ispresent in the mixture at 0.05 wt % to 5 wt % by weight of thethermoplastic polymer.

Clause 45. The method of Clause 33, wherein the nanoparticles have anaverage diameter of 1 nm to 500 nm.

Clause 46. The method of Clause 33, wherein the thermoplastic polymer isselected from the group consisting of: polyamides, polyurethanes,polyethylenes, polypropylenes, polyacetals, polycarbonates, polybutyleneterephthalate (PBT), polyethylene terephthalate (PET), polyethylenenaphthalate (PEN), polytrimethylene terephthalate (PTT),polyhexamethylene terephthalate, polystyrenes, polyvinyl chlorides,polytetrafluoroethenes, polyesters (e.g., polylactic acid), polyethers,polyether sulfones, polyetherether ketones, polyacrylates,polymethacrylates, polyimides, acrylonitrile butadiene styrene (ABS),polyphenylene sulfides, vinyl polymers, polyarylene ethers, polyarylenesulfides, polysulfones, polyether ketones, polyamide-imides,polyetherimides, polyetheresters, copolymers comprising a polyetherblock and a polyamide block (PEBA or polyether block amide), grafted orungrafted thermoplastic polyolefins, functionalized or nonfunctionalizedethylene/vinyl monomer polymer, functionalized or nonfunctionalizedethylene/alkyl (meth)acrylates, functionalized or nonfunctionalized(meth)acrylic acid polymers, functionalized or nonfunctionalizedethylene/vinyl monomer/alkyl (meth)acrylate terpolymers, ethylene/vinylmonomer/carbonyl terpolymers, ethylene/alkyl (meth)acrylate/carbonylterpolymers, methylmethacrylate-butadiene-styrene (MBS)-type core-shellpolymers, polystyrene-block-polybutadiene-block-poly(methylmethacrylate) (SBM) block terpolymers, chlorinated or chlorosulphonatedpolyethylenes, polyvinylidene fluoride (PVDF), phenolic resins,poly(ethylene/vinyl acetate)s, polybutadienes, polyisoprenes, styrenicblock copolymers, polyacrylonitriles, silicones, and any combinationthereof.

Clause 47. The method of Clause 33, wherein the melting point orsoftening temperature of the thermoplastic polymer is 50° C. to 450° C.

Clause 48. The method of Clause 33, wherein the carrier fluid isselected from the group consisting of: silicone oil, fluorinatedsilicone oils, perfluorinated silicone oils, polyethylene glycols,alkyl-terminal polyethylene glycols, paraffins, liquid petroleum jelly,vison oils, turtle oils, soya bean oils, perhydrosqualene, sweet almondoils, calophyllum oils, palm oils, parleam oils, grapeseed oils, sesameoils, maize oils, rapeseed oils, sunflower oils, cottonseed oils,apricot oils, castor oils, avocado oils, jojoba oils, olive oils, cerealgerm oils, esters of lanolic acid, esters of oleic acid, esters oflauric acid, esters of stearic acid, fatty esters, higher fatty acids,fatty alcohols, polysiloxanes modified with fatty acids, polysiloxanesmodified with fatty alcohols, polysiloxanes modified with polyoxyalkylenes, and any combination thereof.

Clause 49. The method of claim 48, wherein the silicone oil is selectedfrom the group consisting of: polydimethylsiloxane,methylphenylpolysiloxane, an alkyl modified polydimethylsiloxane, analkyl modified methylphenylpolysiloxane, an amino modifiedpolydimethylsiloxane, an amino modified methylphenylpolysiloxane, afluorine modified polydimethylsiloxane, a fluorine modifiedmethylphenylpolysiloxane, a polyether modified polydimethylsiloxane, apolyether modified methylphenylpolysiloxane, and any combinationthereof.

Clause 50. The method of Clause 33, wherein the carrier fluid has aviscosity at 25° C. of 1,000 cSt to 150,000 cSt.

Clause 51. The method of Clause 33, wherein the carrier fluid has adensity of 0.6 g/cm³ to 1.5 g/cm³, wherein the thermoplastic polymer hasa density of 0.7 g/cm³ to 1.7 g/cm³.

Clause 52. The method of Clause 33, wherein mixing occurs in anextruder.

Clause 53. The method of Clause 33, wherein mixing occurs in a stirredreactor.

Clause 54. The method of Clause 33, wherein the mixture furthercomprises a surfactant.

Clause 55. The method of Clause 33, wherein the solidified particleshave a D10 of about 0.5 μm to about 125 μm, a D50 of about 1 μm to about200 μm, and a D90 of about 70 μm to about 300 μm, wherein D10<D50<D90.

Clause 56. The method of Clause 33, wherein the solidified particleshave a diameter span of about 0.2 to about 10.

Clause 57. The method of Clause 33, wherein the solidified particleshave a D10 of about 5 μm to about 30 μm, a D50 of about 30 μm to about70 μm, and a D90 of about 70 μm to about 120 μm, wherein D10<D50<D90.

Clause 58. The method of Clause 57, wherein the solidified particleshave a diameter span of about 1.0 to about 2.5.

Clause 59. The method of Clause 33, wherein the solidified particleshave a D10 of about 25 μm to about 60 μm, a D50 of about 60 μm to about110 μm, and a D90 of about 110 μm to about 175 μm, wherein D10<D50<D90.

Clause 60. The method of Clause 59, wherein the solidified particleshave a diameter span of about 0.6 to about 1.5.

Clause 61. The method of Clause 33, wherein the solidified particleshave a D10 of about 75 μm to about 125 μm, a D50 of about 100 μm toabout 200 μm, and a D90 of about 125 μm to about 300 μm, whereinD10<D50<D90.

Clause 62. The method of Clause 61, wherein the solidified particleshave a diameter span of about 0.2 to about 1.2.

Clause 63. The method of Clause 33, wherein the solidified particleshave a circularity of about 0.90 to about 1.0.

Clause 74. The method of Clause 33, wherein the solidified particleshave a Hausner ratio of about 1.0 to about 1.5.

Clause 65. The method of Clause 33, wherein the nanoparticles compriseoxide nanoparticles.

Clause 66. The method of Clause 33, wherein the nanoparticles comprisecarbon black.

Clause 67. The method of Clause 33, wherein the nanoparticles comprisepolymer nanoparticles.

Clause 68. The method of Clause 33, wherein the thermoplastic polymercomprises a thermoplastic elastomer.

Clause 69. The method of Clause 33, wherein the thermoplastic polymer isa thermoplastic elastomer.

Unless otherwise indicated, all numbers expressing quantities ofingredients, properties such as molecular weight, process conditions,and so forth used in the present specification and associated claims areto be understood as being modified in all instances by the term “about.”Accordingly, unless indicated to the contrary, the numerical parametersset forth in the following specification and attached claims areapproximations that may vary depending upon the desired propertiessought to be obtained by the embodiments of the present invention. Atthe very least, and not as an attempt to limit the application of thedoctrine of equivalents to the scope of the claim, each numericalparameter should at least be construed in light of the number ofreported significant digits and by applying ordinary roundingtechniques.

One or more illustrative embodiments incorporating the inventionembodiments disclosed herein are presented herein. Not all features of aphysical implementation are described or shown in this application forthe sake of clarity. It is understood that in the development of aphysical embodiment incorporating the embodiments of the presentinvention, numerous implementation-specific decisions must be made toachieve the developer's goals, such as compliance with system-related,business-related, government-related and other constraints, which varyby implementation and from time to time. While a developer's effortsmight be time-consuming, such efforts would be, nevertheless, a routineundertaking for those of ordinary skill in the art and having benefit ofthis disclosure.

While compositions and methods are described herein in terms of“comprising” various components or steps, the compositions and methodscan also “consist essentially of” or “consist of” the various componentsand steps.

To facilitate a better understanding of the embodiments of the presentinvention, the following examples of preferred or representativeembodiments are given. In no way should the following examples be readto limit, or to define, the scope of the invention.

EXAMPLES Example 1

Polyamide 6 Microparticles were Produced in a Haake Small-Scale doublescrew extruder with high shear rotors. The carrier fluid was PDMS oil ofeither 30,000 cSt or 60,000 cSt viscosity at room temperature. Theconcentrations of components in the final mixture in the extruder areprovided in Table 1. The order of addition of components to the extruderwere either (a) the carrier fluid was added to the extruder, brought totemperature, and then room temperature polymer pellets added to theheated carrier fluid in the extruder or (b) where the polymer pelletswere added to the extruder, brought to temperature, and then roomtemperature carrier fluid added to the molten polymer in the extruder.At temperature (see Table 1), the extruder was operated at 200 rpm for30 minutes. Then, the mixture was discharged from the extruder onto acold surface to provide rapid quench cooling. During heating, attemperature, and cooling, the torque of the extruder system was measuredwith no significant torque detected.

TABLE 1 Sample 1-1 1-2 1-3 1-4 1-5 1-6 1-7 1-8 1-9 wt % polymer 20 20 2020 35 35 35 35 50 carrier fluid 30,000 30,000 60,000 60,000 60,00030,000 30,000 60,000 30,000 visc. (cSt) wt % carrier fluid 80 80 80 8065 65 65 65 50 set temp. (° C.) 220 230 220 230 230 230 220 220 225actual temp. (° C.) 227 236 227 236 236 236 227 227 232 order ofaddition (a) (a) (a) (a) (a) (a) (a) (a) (b)

The resultant mixture was then filtered through a 90 mm WHATMAN® #1paper filter (available from SigmaAldrich) to separate the polyamide 6particles from the carrier fluid. The particles were washed three timeswith 300 mL of ethyl acetate. The particles were then allowed to air dryovernight in an aluminum pan in a fume hood.

The polyamide 6 particles were then characterized for size with aMalvern MASTERSIZER™ 3000 and morphology with SEM micrographs.

TABLE 2 Sample D50 (μm) Diameter Span SEM Micrograph 1-1 64 1.35 FIG. 21-2 35 1.33 FIG. 3 1-3 38 0.92 FIG. 4 1-4 43 0.82 FIG. 5 1-5 76 0.65FIG. 6 1-6 98 0.79 FIG. 7 1-7 104 0.75 FIG. 8 1-8 96 0.83 FIG. 9 1-9 1000.60 FIG. 10

This example illustrated general trends of (a) increasing oil viscositydecreases the particle size and the diameter span (e.g., comparing 1-1to 1-3 and comparing 1-6 to 1-5), (b) increasing polymer loadingincreases the particle size and decreases the diameter span (e.g.,comparing 1-4 to 1-5 and comparing 1-1 to 1-7), and (c) increasingprocessing temperature decreases the particle size and the diameter span(e.g., comparing 1-8 to 1-5 and comparing 1-1 to 1-2).

Additionally, inductively coupled plasma was performed on the particleshaving been digested in HNO₃/HF/H₂O₂ mixture using a closed-vesselmicrowave or oven for digestionto determine the silica content, whichrelates to the residual PDMS. The amount of silica found in the ninesamples ranged from about 234 ppm to about 374 ppm. For the sample withabout 234 ppm of silica, it is estimated that there is only about 0.62 gof PDMS present per 1000 g of particles. Without being limited bytheory, it is believed that said PDMS is present primarily on thesurface of the particles.

Example 2

Polyamide 12 microparticles were produced in a 25 mm twin-screw extruder(Werner & Pfleiderer ZSK-25). The carrier fluid was PDMS oil with 10,000cSt viscosity at room temperature. The concentrations of components inthe final mixture in the extruder are provided in Table 3. The polymerpellets were added to the extruder, brought to temperature, and thenpreheated carrier fluid having AEROSIL® R812S silica nanoparticlesdispersed therein added to the molten polymer in the extruder. Otheroperational parameters are provided in Table 3. Then the mixture wasdischarged into a container and allowed to cool to room temperature overseveral hours. The light scattering particle size data is also providedin Table 3.

TABLE 3 Sample 2-1 2-2 2-3 2-4 2-5 2-6 Screw RPM 900 1100 1100 900 9001100 wt % polyamide 12* 47 47 47 47 38 38 wt % silica** 1.1 1.1 1.1 1.11.1 1.1 Temp. (° C.) 230 230 250 250 230 230 D10 (μm) 30.5 31.2 26.225.4 35.6 54.2 D50 (μm) 57.8 50.3 38.1 38.5 72.8 111 D90 (μm) 101 80.155.3 57.9 131 220 *relative total combined weight of PDMS oil andpolyamide **relative to polyamide

Example 3

ELASTOLLAN® 1190A10 thermoplastic polyurethane (TPU) added to the 25 mmtwin-screw extruder (Werner & Pfleiderer ZSK-25), brought totemperature, and then preheated 10,000 cSt PDSM oil having AEROSIL® RX50silica nanoparticles dispersed therein added to the molten polymer inthe extruder. The extruder conditions and results are presented in Table4.

TABLE 4 Ex- truder Screw Temp wt % wt % D10 D50 D90 Sample RPM (° C.)TPU* silica** Silica (μm) (μm) (μm) 3-1 1100 240 53 1.3 RX50 54.2 69.086.6 3-2 900 240 53 1.3 RX50 59.2 74.5 94.8 3-3 1100 240 53 1.3 RX5057.6 75.3 97.8 3-4 1100 240 53 1.3 RX50 49.5 65.1 85.0 3-5 1100 240 422.1 RX50 26.3 41.9 65.1 3-6 1100 240 42 2.1 RX50 28.9 42.0 60.2 3-7 1100240 50 1.00 RX50 56.5 76.3 103.0 3-8 1100 240 46 1.17 RX50 44.6 61.784.7 3-9 1100 260 46 1.17 RX50 38.2 46.5 56.5 3-10 1100 260 51 0.96 RX5053.5 64.0 75.7 3-11 1100 260 53 0.59 R812S 21.3 26.1 32.3 3-12 1100 26051 0.64 R812S 19.5 24.0 29.7 3-13 1100 240 48 0.72 R812S 15.2 25.0 38.83-14 1100 240 52 0.62 R812S 20.8 35.1 57.5 3-15 1100 240 53 0.39 R812S44.3 59.8 80.5 3-16 1100 240 47 0.50 R812S 21 34.8 54.8 3-17 1100 260 540.37 R812S 35.6 43.0 51.7 *relative to total combined weight of PDMS oiland TPU **relative to TPU

Example 4

A 1 L stirred reactor from Parr Instruments was used to preparepolyamide 6 particles by melt emulsification. The reactor was loadedwith 20 wt % polyamide 6 and 80 wt % 10,000 cSt PDMS oil. The mixturewas then heated to 225° C. while stirring at 1000 rpm using a dual4-blade propeller. After about 60 minutes, the mixture was dischargedfrom the reactor onto dry ice to quench the mixture. The mixture wasthen filtered and washed to recover the polymer particles. The resultantpolymer particles were passed through a 150-μm sieve. Approximately, 40wt % of the polyamide 6 loaded into the reactor passed through the150-μm sieve. FIG. 11 is an SEM micrograph of the particles aftersieving, which illustrates the range of particle sizes as large.

Example 5

A 2 L glass reactor from Buchi AG was used to prepare polyamide 12particles by melt emulsification. The reactor was loaded with 1 wt %AEROSIL® R812S silica nanoparticles (by weight of the polyamide 12 inthe final mixture) in 10,000 cSt PDMS oil. The mixture was heated to200° C. before adding 23 wt % polyamide 12 pellets relative to thecombined weight of the PDMS oil and polyamide 12. The reactor was mixedat 500 rpm for 30 minutes. The resultant mixture was discharged andcooled to ambient temperate at a rate of about 1° C. to about 3° C. perminute. The mixture was then washed with heptane and filtered through a90 mm WHATMAN® #1 paper filter to recover the polymer particles. Theresultant polymer particles were air dried overnight in a fume hood. Thedried particles have a D50 of about 227 μm, and the dried particlespassed through a 150-μm sieve have a D50 of about 124 μm.

Example 6

Polyamide 12 particles (Examples 6-1 to 6-44) were prepared by meltemulsification in a 1 L glass kettle reactor. 10,000 cSt PDMS oil, 23%polyamide 12 (from RTP, EMX-Grivory, or from Arkema) relative to thecombined weight of the PDMS oil and polyamide 12, and a desired amountof silica nanoparticles (AEROSIL® R812S or AEROSIL® RX50) by weight ofpolyamide 12 were added to the glass kettle. The order of addition waseither (c) PDMS oil and silica nanoparticles mixed to a good dispersionthen polyamide added or (d) PDMS oil, polyamide, and silicananoparticles added before mixing. The nitrogen headspace purge was thenturned on, and the mixture heated to a desired temperature (e.g., 200°C., 210° C., or 220° C.) over 90 minutes at 260 rpm. Once attemperature, the rotor speed was increased to a desired rpm. Sampleswere taken at various times. Once complete, heating and stirring wereturned off, and the reactor was allowed to cool to room temperaturebefore discharging the mixture. The resultant mixture was filtered andwashed with heptane. The resultant particles were allowed to air dryovernight in a fume hood. Optionally, the dried particles were screened(scr) through a 150-μm sieve. Table 5 lists the experimental details andresultant particle properties.

For Samples 6-45 to 6-47, a 2 L stainless reactor from Buchi AG was usedto prepare polyamide 12 particles by melt emulsification. The reactorwas loaded with 0.67 wt % AEROSIL® R812S silica nanoparticles (by weightof the polyamide 12 in the final mixture) in 60,000 cSt PDMS oil and wassealed without N2 purge. The mixture was heated to 250° C. at rampingrate of 3.68° C./min before adding 30 wt % polyamide 12 pellets relativeto the combined weight of the PDMS oil and polyamide 12. When thereactor temperature reached 245° C., slowly opened vent valve and purgedreactor with N2 at flow rate of 2-3 scfh. The reactor was mixed at 650rpm for 60 minutes. The resultant mixture was cooled down with gentlestirring at 50 rpm to less than 60° C. and discharged. The processsamples taken 40 min, 60 min and final room temp. were then washed withheptane and filtered through a 90 mm WHATMAN® #1 paper filter to recoverthe polymer particles. The resultant polymer particles were air driedovernight in a fume hood. The dried particles have a D50 of about 21.3μm, and the final dried particles passed through a 150-μm sieve have aD50 of about 21.5 μm.

For Samples 6-48 to 6-50, a 2 L stainless reactor from Buchi AG was usedto prepare polyamide 12 particles by melt emulsification. The reactorwas loaded with 0.67 wt % AEROSIL® R812S silica nanoparticles (by weightof the polyamide 12 in the final mixture) in 60,000 cSt PDMS oil and waspurged with N2 at flow rate of 2-3 scfh. The mixture was heated to 250°C. at ramping rate of 3.68° C./min before adding 30 wt % polyamide 12pellets relative to the combined weight of the PDMS oil and polyamide12. The reactor was mixed at 650 rpm for 60 minutes. The resultantmixture was cooled down with gentle stirring at 50 rpm to less than 60°C. and discharged. The process samples taken 50 min, 60 min time pointand at room temp. were then washed with heptane and filtered through a90 mm WHATMAN® #1 paper filter to recover the polymer particles. Thefinal room temp. sample was aggregated and the particle size was notmeasured. The resultant polymer particles taken at 60 min were air driedovernight in a fume hood. The dried particles have a D50 of about 25.8μm, and the dried particles passed through a 150-μm sieve have a D50 ofabout 26.4 μm.

For Samples 6-51 to 6-53, a 2 L stainless reactor from Buchi AG was usedto prepare polyamide 12 particles by melt emulsification. The reactorwas loaded with 0.67 wt % AEROSIL® R812S silica nanoparticles (by weightof the polyamide 12 in the final mixture) in 60,000 cSt PDMS oil and waspurged with N2 at 2-3 flow rate of scfh. The mixture was heated to 250°C. at ramping rate of 5.68° C./min before adding 30 wt % polyamide 12pellets relative to the combined weight of the PDMS oil and polyamide12. The reactor was mixed at 650 rpm for 60 minutes. The resultantmixture was cooled down with gentle stirring at 50 rpm to less than 60°C. and discharged. The process samples taken at 60 min time point and atroom temp. were then washed with heptane and filtered through a 90 mmWHATMAN® #1 paper filter to recover the polymer particles. The finalroom temp. sample was aggregated and the particle size was not measured.The resultant polymer particles taken at 60 min were air dried overnightin a fume hood. The dried particles have a D50 of about 33.8 μm, and thedried particles passed through a 150-μm sieve have a D50 of about 34.9μm.

TABLE 5 Set Order Silica Screened Particle Size Not Screened ParticleSize Yield (wt %) Temp Time of (wt % and (μm or unitless) (μm orunitless) Not Sample (° C.) RPM (min) Add. PA-12 type) D10 D50 D90 SpanD10 D50 D90 Span Scr Scr 6-1 220 600 10 (c) EMS-Griv. 1% R812S 46.5 87.1146 1.14 77.5 72.7 6-2 26 57.2 90.6 137 0.89 83.8 68.8 6-3 30 48.4 78.7124 0.96 92.0 67.7 6-4 50 53.4 84.7 128 0.89 93.9 57.6 6-5 220 600 15(c) EMS-Griv. 1% R812S 34.9 76.3 131 1.99 90.8 74.3 6-6 220 1250 10 (c)EMS-Griv. 1% R812S 16.2 43.8 103 1.98 92.7 71.4 6-7 20 19.3 44 95.5 1.7394.3 69.6 6-8 30 20 44.4 97.2 1.74 96.4 71.9 6-9 40 21 43.8 92.7 1.6487.2 80 6-10 RT 21.1 44.4 91.7 1.59 99.2 72.1 6-11 220 1250 40 (c)EMS-Griv. 1% R812S 16.7 49.5 108 1.85 95.7 82.1 6-12 100  21.5 50.9 1061.65 94.9 84.6 6-13 160  23.1 51.4 106 1.61 92.6 89.3 6-14 220  21.949.8 104 1.64 92.6 90.6 6-15 RT 22.9 52 108 1.64 94.3 91.1 6-16 220 125015 (c) RTP 1% R812S 12 46 104 1.41 6-17 220 1250 40 (d) RTP 0.33% R812S46.7 8.35 139 1.02 97.3 77.4 6-18 90 53.1 89.5 144 1.02 95.4 78.7 6-19210 1250 15 (d) RTP 0.33% R812S 44.2 70.7 112 0.96 94.7 80.8 6-20 4046.1 71.7 111 0.90 92.6 8.6 6-21 90 49.8 78.9 124 0.94 88.7 90.6 6-22 RT50.2 78.9 123 0.93 93.5 88.3 6-23 200 1250 15 (d) RTP 0.33% R812S 56.684.4 125 0.81 49.7 85.5 169 1.40 93.3 89.2 6-24 40 58 84.8 124 0.77 52.486.2 154 1.18 91.5 95.5 6-25 90 61.1 86.7 123 0.71 53.3 84.9 142 1.0592.1 89.7 6-26 RT 59.4 84.6 121 0.73 54 89.4 166 1.25 93.3 91.8 6-27 2201250 15 (d) RTP 1% R812S 16.2 43.9 95 1.79 17.8 54.8 300 5.15 96.0 83.36-28 40 19.8 46.3 96.7 1.66 19.7 53.3 263 4.57 95.4 97.9 6-29 90 21.147.7 106 1.79 21 49 220 4.05 96.4 84.8 6-30 RT 20.5 45.1 96.9 1.69 20.849.7 210 3.85 96.7 91.5 6-31 220 1250 15 (d) RTP 1% RX50 37.2 66.1 1161.17 35.4 71.2 252 3.04 98.2 85.5 6-32 40 37.6 67.7 118 1.87 93.8 84.86-33 90 39.4 67.4 115 1.12 36.7 72.1 239 2.81 95.2 84.8 6-34 RT 36.4 65113 1.18 36 73.2 254 2.98 96.1 88.5 6-35 220 1250 15 (d) RTP 0.33% RX50101 125 135 0.94 101 125 135 0.43 94.7 29.7 6-35 40 99.5 128 164 0.51108 172 271 0.95 94.7 25.5 6-36 90 102 129 162 0.46 116 175 265 0.8594.7 21.2 6-37 RT 98.7 121 151 0.43 113 170 255 0.83 84.2 15.2 6-38 2201250 40 (d) EMS-Griv. 0.33% R812S 56.6 79.9 112 0.688 51.4 87.6 2161.884 90.2 81.8 6-39 90 60.7 87.1 124 0.729 56.5 95.5 218 1.688 90.577.6 6-40 RT 66.7 93.8 132 0.702 60.9 100 196 1.35 92.1 80.1 6-41 2201250 15 (d) Ark. 1% R812S 6-42 40 52.4 79.4 121 0.864 50 83.8 159 1.30293.4 89.4 6-43 90 55.5 82.6 122 0.81 49.3 80 138 1.103 92.4 83.2 6-44 RT6-45 250 650 40 RTP 0.67% R812S 14.5 20.3 28.5 0.69 14.1 20.1 28.5 0.7298.42 96.6 6-46 60 12.6 20.0 31.1 0.93 12.1 19.8 32.4 1.02 96.97 94.26-47 RT 15.4 21.5 29.8 0.67 15.1 21.3 29.8 0.69 97.48 96.9 6-48 250 25050 RTP 0.67% R812S 14.9 25.3 40.5 1.01 13.4 24.8 41.6 1.14 97.45 96.06-49 60 14.3 26.4 45.0 1.17 13.4 25.8 46.4 1.28 98.05 93.6 6-50 RT 6-51250 650 40 RTP 0.67% R812S 6-52 60 19.2 34.9 59.1 1.15 17.8 33.8 58.71.21 97.86 91.3 6-53 RT “RT” refers to once the mixture has cooled toreach room temperature. Blank cells indicated values not measured.

FIG. 12 illustrates SEM micrographs for sample 6-4. FIG. 13 illustratesSEM micrographs for sample 6-10. FIG. 14 illustrates SEM micrographs forsample 6-15. FIG. 15 illustrates SEM micrographs for sample 6-26. FIG.16 illustrates SEM micrographs for sample 6-30. FIGS. 17-20 illustrateSEM micrographs for samples 6-31, 6-32, 6-33, and 6-34.

This example illustrates that decreasing the concentration of silicananoparticles in the mixture increases the particle size but decreasesthe diameter span (e.g., comparing 6-17 through 6-18 to 6-28 through6-29). Further, increasing the temperature decrease the particle sizebut increase the diameter span (e.g., comparing 6-17 through 6-18, 6-20through 6-21, and 6-24 through 6-25). It also appears that the time ofmixing beyond about 10 minutes has minimal effect on the particle sizeand diameter span.

Example 7

SEM micrographs were taken of commercially available polyamideparticulate material used for 3D printing, see Table 6.

TABLE 6 Sample SEM Micrographs ADSINT ™ PA11 FIG. 21 ADSINT ™ PA12L FIG.22 ADSINT ™ PA12 FIGS. 23A and 23B SINTRATEC ™ PA12 FIG. 24

Comparing the SEM micrographs for the commercially available samples tothose of samples 6-4, 6-10, 6-15, 6-26, 6-30, 6-31, 6-32, 6-33, and 6-34of Example 4, the particles produced by the methods described hereinhave a greater circularity and higher silica nanoparticle coverage onthe surface of the polyamide particles.

Example 8

Three sets of samples were prepared with polyamide 12 from RTP. 10,000cSt PDMS, 23 wt % polyamide 12 relative to the weight of PDMS andpolyamide combined, 1 wt % AEROSIL® R812S silica nanoparticles relativeto the weight of the polyamide, and optionally surfactant (wt % relativeto the weight of the polyamide) were placed in a glass kettle reactor.The headspace was purged with argon and the reactor was maintained underpositive argon pressure. The components were heated to over 220° C. overabout 60 minutes with 300 rpm stirring. At temperature, the rpm wasincreased to 1250 rpm. The process was stopped after 90 minutes andallowed to cool to room temperature while stirring. The resultantmixture was filtered and washed with heptane. A portion of the resultantparticles was screened (scr) through a 150-μm sieve. Table 7 includesthe additional components of the mixture and properties of the resultantparticles.

TABLE 7 Max Reactor Screened Particle Size Not Screened Particle SizeTemp. (μm or unitless) (μm or unitless) Sample Surfactant (° C.) D10 D50D90 Span D10 D50 D90 Span 8-1 none 223 16.7 37.4 77.3 1.62 16.9 38.7 1222.72 8-2 2.5% CALFAX ® 226 44.2 67.7 105 0.90 41.4 68.1 131 1.32 DB-458-3 1% docusate 226 19.2 43.3 95.8 1.77 19.4 48.8 207 3.84 sodium

FIGS. 25 and 26 are the volume density particle size distribution forthe particles screened and not screened, respectively.

Example 9

This example illustrates that the inclusion of surfactant and thecomposition of said surfactant can be another tool used to tailor theparticle characteristics.

In this example, powder flow of polyurethane particulates wascharacterized through sieving and angle of repose measurements. Thesieved yield of the polyurethane particulates was determined by exposinga quantity of polyurethane particulates to a 150 μm U.S.A. StandardSieve (ASTM E11) and determining the fraction by mass of particulatespassing through the sieve relative to the total quantity of polyurethaneparticulates. The sieve was used manually without particular conditionsof duration of force. Angle of repose measurements were performed usinga Hosokawa Micron Powder Characteristics Tester PT-R using ASTM D6393-14“Standard Test Method for Bulk Solids” Characterized by Carr Indices.”

In this example, average particle size measurements and particle sizedistributions were determined by optical digital microscopy. The opticalimages were obtained using a Keyence VHX-2000 digital microscope usingversion 2.3.5.1 software for particle size analysis (system version1.93). In some instances, D₁₀, D₅₀ and D₉₀ measurements were made usinga Malvern MASTERSIZER™ 3000 Aero S particle size analyzer, which useslight scattering techniques for particle size measurement.

For light scattering techniques, glass bead control samples with adiameter within the range of 15 μm to 150 μm under the tradename QualityAudit Standards QAS4002™ obtained from Malvern Analytical Ltd. may beused. Samples may be analyzed as dry powders dispersed in air using thedry powder dispersion module of the MASTERSIZER™ 3000 Aero S. Particlesizes may be derived using the instrument software from a plot of volumedensity as a function of size.

Comparative Example 9-1

To a 500 mL glass reactor, 160 g polydimethylsiloxane (PSF-30000,Clearco) was added. The reactor was set to a stirring rate of 200 rpm,and the temperature was raised to 190° C. under an atmosphere ofnitrogen gas. Further heating to 200° C. was performed, at which point,40 g thermoplastic polyurethane pellets were added to the stirringpolydimethylsiloxane. The thermoplastic polyurethane waspoly[4,4′-methylenebis(phenylisocyanate)-alt-1,4-butanediol/di(propylene glycol)/polycaprolactone]with hardness Shore A 84 (Sigma-Aldrich). Once the thermoplasticpolyurethane pellets were fully combined with the polydimethylsiloxane,the stirring rate was increased to 500 rpm and the temperature wasmaintained at 200° C. for 60 minutes. Thereafter, stirring wasdiscontinued and the resulting slurry was allowed to cool to roomtemperature. The slurry was washed twice with hexane, and thermoplasticpolyurethane particulates were obtained following vacuum filtration.

The thermoplastic polyurethane particulates were then passed through a150 μm sieve, and particulates passing through the sieve werecharacterized by optical imaging. FIG. 27 shows an illustrative opticalmicroscopy image at 150× magnification of thermoplastic polyurethaneparticulates obtained in Comparative Example 9-1. The average particlesize was approximately 100 μm and a wide distribution of particle sizeswas obtained.

Comparative Example 9-2

The thermoplastic polyurethane particulates from Comparative Example 9-1were collected after filtration but before sieving and combined with0.25 wt. % fumed silica particulates functionalized withhexamethyldisilazane (AEROSIL® RX50). The thermoplastic polyurethaneparticulates were then dry blended with the fumed silica particulatesusing an SKM Mill for 30 seconds at a blending rate of 170 rpm.

The dry-blended particulates were then passed through a 150 μm sieve andcharacterized by optical imaging and SEM. FIG. 28 shows an illustrativeoptical microscopy image of thermoplastic polyurethane particulatesobtained in Comparative Example 9-2. FIGS. 29A and 29B show illustrativeSEM images of thermoplastic polyurethane particulates obtained inComparative Example 9-2 at various magnifications. The average particlesize was approximately 100 μm and a wide distribution of particle sizeswas obtained, similar to that of Comparative Example 9-1. There was noevidence of silica particle embedment upon the surface of thethermoplastic polyurethane particulates. Moreover, there was no apparentformation of a uniform silica coating upon the polyurethane particulates

Example 9-1

Comparative Example 9-1 was repeated, except 0.25 wt. % of fumed silicaparticulates functionalized with hexamethyldisilazane (AEROSIL® R812S)was combined with the polydimethylsiloxane prior to heating the reactorto temperature and adding the thermoplastic polyurethane particulates.

The thermoplastic polyurethane particulates were then passed through a150 μm sieve, and particulates passing through the sieve werecharacterized by optical imaging. FIG. 30 shows an illustrative opticalmicroscopy image of thermoplastic polyurethane particulates obtained inExample 9-1. The average particle size was approximately 12±16 μm. FIG.31 shows an illustrative histogram of the particle sizes ofthermoplastic polyurethane particulates obtained in Example 9-1.

Example 9-2

Example 9-1 was repeated, except 1.00 wt. % of the same fused silicaparticulates was used. In addition, the slurry was washed three timeswith hexanes instead of twice.

The thermoplastic polyurethane particulates were then passed through a150 μm sieve, and particulates passing through the sieve werecharacterized by optical imaging. FIG. 32 shows an illustrative opticalmicroscopy image of thermoplastic polyurethane particulates obtained inExample 9-2. The average particle size was approximately 34±19 μm. FIG.33 shows an illustrative histogram of the particle sizes ofthermoplastic polyurethane particulates obtained in Example 9-2.

Example 9-3

Example 9-1 was repeated, except the type of fumed silica particulateswas changed to AEROSIL® RX50. In addition, the slurry was washed fourtimes with heptane instead of twice with hexanes.

The thermoplastic polyurethane particulates were then passed through a150 μm sieve, and particulates passing through the sieve werecharacterized by optical imaging and SEM. FIG. 34 shows an illustrativeoptical microscopy image of thermoplastic polyurethane particulatesobtained in Example 9-3. FIGS. 35A and 35B show illustrative SEM imagesof thermoplastic polyurethane particulates obtained in Example 9-3 atvarious magnifications. The average particle size by optical imaging wasapproximately 48±20 μm, and the angle of repose was 32.0°. FIG. 36 showsan illustrative histogram of the particle sizes of thermoplasticpolyurethane particulates obtained in Example 9-3.

The particle size distribution determined by the Malvern Mastersizerparticle size analyzer provided D₁₀, D₅₀ and D₉₀ values of 40.7 μm, 68.2μm and 109 μm, respectively, thereby affording a span of 1.001.

Example 9-4

Example 9-1 was repeated, except the type of thermoplastic polyurethanepellets was changed to ELASTOLLAN® 1190A obtained from BASF. ELASTOLLAN®1190A is a polyether polyurethane elastomer with a hardness Shore A 90.

The thermoplastic polyurethane particulates were then passed through a150 μm sieve, and particulates passing through the sieve werecharacterized by optical imaging and SEM. FIG. 37 shows an illustrativeoptical microscopy image of thermoplastic polyurethane particulatesobtained in Example 9-4. FIGS. 38A-D show illustrative SEM images ofthermoplastic polyurethane particulates obtained in Example 9-4 atvarious magnifications. The average particle size by optical imaging wasapproximately 68±29 μm, and the angle of repose was 29.9°. FIG. 39 showsan illustrative histogram of the particle sizes of thermoplasticpolyurethane particulates obtained in Example 9-4.

The particle size distribution determined by the Malvern Mastersizerparticle size analyzer provided D₁₀, D₅₀ and D₉₀ values of 61.0 μm, 95.6μm and 146 μm, respectively, thereby affording a span of 0.889.

Example 9-5

Example 9-4 was repeated, except processing was conducted at one-halfthe scale of Example 9-4.

The thermoplastic polyurethane particulates were then passed through a150 μm sieve, and particulates passing through the sieve werecharacterized by optical imaging and SEM. FIG. 40 shows an illustrativeoptical microscopy image of thermoplastic polyurethane particulatesobtained in Example 9-5. FIGS. 41A-41C show illustrative SEM images ofthermoplastic polyurethane particulates obtained in Example 9-5 atvarious magnifications. The average particle size by optical imaging wasapproximately 61±17 μm. FIG. 42 shows an illustrative histogram of theparticle sizes of thermoplastic polyurethane particulates obtained inExample 9-5.

The particle size distribution determined by the Malvern MASTERSIZER™particle size analyzer provided D₁₀, D₅₀ and D₉₀ values of 52.6 μm, 71.7μm and 97.2 μm, respectively, thereby affording a span of 0.622.

Comparison of Results. Tables 8A and 8B below summarize the formationconditions used for Comparative Examples 9-1 and 9-2 and Examples 9-1through 9-5 and the properties of the thermoplastic polyurethaneparticulates obtained in each instance. Solids loading was calculated bydividing the mass of thermoplastic polyurethane by the combined mass ofthermoplastic polyurethane and polydimethylsiloxane.

TABLE 8A Comp. Comp. Example Example Example Example 9-1 9-2 9-1 9-2Solids Loading 20% 20% 20% 20% Thermoplastic 40 g 40 g 40 g 80 gPolyurethane (TPU) Poly(dimethylsiloxane) 160 g 160 g 160 g 320 g (PDMS)PDMS Viscosity 30,000 cSt 30,000 cSt 30,000 cSt 30,000 cSt Fumed SilicaNone 40 nm 7 nm 7 nm (wt. %) (0.25%) (0.25%) (1.00%) Blending ProcessMelt Emuls. Dry Blend Melt Emuls. Melt Emuls. Reactor 500 mL 500 mL 500mL 500 mL Kettle Kettle Kettle Kettle Temperature 200° C. 200° C. 200°C. 200° C. RPM 500 500 500 500 Reaction Time 60 min 60 min 60 min 60 minWashing Hexane x 2 Hexane x 2 Hexane x 2 Hexane x 3 Pre-Sieving Mass 96%96% 70% 78% Recovery Sieved Yield (150 μm) Cannot sieve 0.8%  40% 43%Average Particle Size ~100 μm ~100 μm 12 ± 16 μm 34 ± 19 μm by OpticalMicroscopy D₁₀ (μm) D₅₀ (μm) D₉₀ (μm) Span Digital Microscope FIG. 27FIG. 28 FIG. 30 FIG. 32 Images (150X) (100X) (250X) (150X) SEM ImagesFIGS. 29A/29B Histogram FIG. 31 FIG. 33 Angle of repose

TABLE 8B Example Example Example 9-3 9-4 9-5 Solids Loading 20% 20% 20%Thermoplastic 80 g 80 g 40 g Polyurethane (TPU) Poly(dimethylsiloxane)320 g 320 g 160 g (PDMS) PDMS Viscosity 30,000 cSt 30,000 cSt 30,000 cStFumed Silica 40 nm 40 nm 40 nm (wt. %) (0.25%) (0.25%) (0.25%) BlendingProcess Melt Emuls. Melt Emuls. Melt Emuls. Reactor 500 mL 500 mL 500 mLKettle Kettle Kettle Temperature 200° C. 200° C. 200° C. RPM 500 500 500Reaction Time 60 min 60 min 60 min Washing Heptane x 4 Heptane x 4Heptane x 4 Pre-Sieving Mass 89-95% 97% 96% Recovery Sieved Yield (150μm) 80-83% 73% 87% Average Particle Size 48 ± 20 μm 68 ± 29 μm 61 ± 17μm by Optical Microscopy D₁₀ (μm) 40.7 61.0 52.6 D₅₀ (μm) 68.2 95.6 71.7D₉₀ (μm) 109 146 97.2 Span 1.001 0.889 0.622 Digital Microscope FIG. 34FIG. 37 FIG. 40 Images (150X) (150X) (150X) SEM Images FIGS. FIGS. FIGS.35A/35B 38A-38D 41A-41C Histogram FIG. 36 FIG. 39 FIG. 42 Angle ofrepose 32.0° 29.9°As shown in Tables 8A and 8B and the accompanying FIGS., there was awide particle size distribution and some particulate coalescence in theabsence of a fused silica emulsion stabilizer (Comparative Examples 9-1and 9-2). Different loadings and sizes of fused silica particlesafforded narrower particle size distributions and variations in averageparticle size (Examples 9-1 through 9-3). Different thermoplasticpolyurethanes also led to variance in the average particle size obtained(Examples 9-3 and 9-4). The processing scale also impacted the particlesize distribution as well (Examples 9-4 and 9-5).

Comparing the SEM images, there was fairly uniform coverage of silicananoparticles upon the surface of the thermoplastic polyurethaneparticulates obtained by melt emulsification (Examples 9-3 through 9-5;FIGS. 35A/10B, 38A-13D and 41A-41C). The thermoplastic polyurethaneparticulates obtained in Example 9-5, which had a narrower particle sizedistribution, had a more even coverage/distribution of silicananoparticles than did the comparable thermoplastic polyurethaneparticulates prepared in Example 9-4, which had a wider particle sizedistribution.

In contrast to thermoplastic polyurethane particulates produced by meltemulsification with silica nanoparticles, dry blending of thermoplasticpolyurethane particulates with silica nanoparticles resulted in little,if any, coverage of silica nanoparticles on the thermoplasticpolyurethane particulates (Comparative Example 9-2; FIGS. 29A/29B).

Another comparative example of thermoplastic polyurethane particulatesis ADSINT TPU 90A NAT from ADVANC3D, which is a 3-D printingcomposition. ADSINT TPU 90A NAT thermoplastic polyurethane particulateshave an irregular particulate shape, as shown in the SEM images of FIGS.43A-43E. Based on the SEM images of FIGS. 43B and 43C there is an unevendistribution of emulsion stabilizers on the surface of ADSINT TPU 90Aparticulates. Particulates that are irregular in shape and have a roughsurface tend to have an uneven distribution of emulsion stabilizers onthe surface, and agglomeration in rough areas and crevices may occur, asshown in the SEM images of FIGS. 43C and 43D. The cross-sectional SEMimage of FIG. 43E shows the presence of emulsion stabilizers in limitedareas with a non-uniform distribution around the particulate.

Substantially spherical particulates with a smooth surface, as producedin Examples 9-1 through 9-5, may afford incorporation of emulsionstabilizers in a homogeneous manner around the outer surface of eachparticulate. Substantially homogeneous incorporation of emulsionstabilizers upon the particulates may aid in achieving uniformproperties and consistent performance for the corresponding bulkmaterials, such as powder flow characteristics and processingproperties.

Example 10

Selective laser sintering (SLS) was performed using a Snow White SLSprinter system (Sharebot). The thermoplastic polyurethane particulatesof Example 9-3 were deposited using the SLS printer system in a 30 mm×30mm square and then sintered under various laser power conditionsspecified in Table 9 below. Void percentage following sintering wascalculated using the digital microscope software.

TABLE 9 Laser Length × Power Scan Temp. Width % Entry (%) Rate¹ (° C.)Comments (mm) Voids 1 20 40,000 108 No sintering. 2 25 40,000 108Sintered. 30,162 × 0.098 Lots of powder 30,105 on backside. 3 30 40,000108 Sintered. 29,930 × 0.58 Lots of powder 30,034 on backside. 4 3540,000 108 Sintered. 30,234 × 0.13 Lots of powder 30,380 on backside. 540 40,000 108 Sintered. 30,230 × 0.029 Lots of powder 30,035 onbackside. ¹Multiplying the reported scan rate by 0.04 gives the scanrate in mm/s.

As shown, effective sintering was realized at a laser power above 20%,up to a power of 40% (highest value tested) to afford low-porositymaterials having under 1% voids, many times under 0.1% voids. Theobserved powder formation is believed to artificially lower the amountof voids measured. In any event, the low void percentage ischaracteristic of effective fusing of the thermoplastic polyurethaneparticulates with one another. As a representative example, FIG. 44shows an optical image of the printed product obtained from Entry 5 ofExample 10.

Example 11

In this example, powder flow of polyurethane particulates wascharacterized through sieving and angle of repose measurements. Thesieved yield of the polyurethane particulates was determined by exposinga quantity of polyurethane particulates to a 150 μm U.S.A. StandardSieve and determining the fraction by mass of particulates passingthrough the sieve relative to the total quantity of polyurethaneparticulates. The sieve was used manually without particular conditionsof duration of force. Angle of repose measurements were performed usinga Hosokawa Micron Powder Characteristics Tester PT-R using ASTM D6393-14“Standard Test Method for Bulk Solids” Characterized by Can Indices.”

In this example, average particle size (D₅₀), D₁₀ and D₉₀ measurementswere made using a Malvern MASTERSIZER™ 3000 Aero S particle sizeanalyzer. Optical images were obtained using a Keyence VHX-2000 digitalmicroscope using version 2.3.5.1 software for particle size analysis(system version 1.93). An average particle size was also obtained byprocessing the optical image.

Comparative Example 11-1

To a 500 mL glass reactor, 160 g polydimethylsiloxane (PSF-30000,Clearco) was added. The reactor was set to a stirring rate of 350 rpmusing an overhead stirrer, and the temperature was raised to 190° C.Further heating to 200° C. was performed, at which point, 40 gthermoplastic polyurethane pellets were added to the stirringpolydimethylsiloxane. The thermoplastic polyurethane waspoly[4,4′-methylenebis(phenylisocyanate)-alt-1,4-butanediol/di(propylene glycol)/polycaprolactone](Sigma-Aldrich). Once the thermoplastic polyurethane pellets were fullycombined with the polydimethylsiloxane, the stirring rate was increasedto 500 rpm and the temperature was maintained at 200° C. for 60 minutes.Thereafter, stirring was discontinued and the resulting slurry wasallowed to cool to room temperature. The slurry was washed four timeswith heptane, and thermoplastic polyurethane particulates were obtainedfollowing vacuum filtration.

The thermoplastic polyurethane particulates were then passed through a150 μm sieve, and particulates passing through the sieve werecharacterized by optical imaging. FIG. 45 shows an illustrative opticalmicroscopy image at 150× magnification of thermoplastic polyurethaneparticulates obtained in Comparative Example 11-1. The average particlesize was 97.1 μm and a wide distribution of particle sizes was obtained(span=1.239). FIG. 46 shows an illustrative histogram of the particlesizes of thermoplastic polyurethane particulates obtained in ComparativeExample 11-1.

Comparative Example 11-2

To a 500 mL glass reactor, 320 g polydimethylsiloxane (PSF-30000,Clearco) was added along with 0.25 wt. % fumed silica particulatesfunctionalized with hexamethyldisilazane (AEROSIL® RX50 from Evonik,35±10 m²/g BET surface area and 40 nm average particle size). Thereactor was set to a stirring rate of 200 rpm using an overhead stirrer,and the temperature was raised to 190° C. Further heating to 200° C. wasperformed, at which point, 80 g thermoplastic polyurethane pellets wereadded to the stirring polydimethylsiloxane. The thermoplasticpolyurethane in this instance was ELASTOLLAN® 1190A, a polyetherpolyurethane elastomer obtained from BASF. Once the thermoplasticpolyurethane pellets were fully combined with the polydimethylsiloxane,the stirring rate was increased to 500 rpm and the temperature wasmaintained at 200° C. for 60 minutes. Thereafter, stirring wasdiscontinued and the resulting slurry was allowed to cool to roomtemperature. The slurry was washed four times with hexanes, andthermoplastic polyurethane particulates were obtained following vacuumfiltration.

The thermoplastic polyurethane particulates were then passed through a150 μm sieve, and particulates passing through the sieve werecharacterized by optical imaging. FIG. 47 shows an illustrative opticalmicroscopy image at 150× magnification of thermoplastic polyurethaneparticulates obtained in Comparative Example 11-2. The average particlesize was 95.6 μm and a wide distribution of particle sizes was obtained(span=0.892). The angle of repose was 29.9°. FIGS. 48A and 48B showillustrative SEM images of thermoplastic polyurethane particulatesobtained in Comparative Example 11-2 at various magnifications. FIG. 49shows an illustrative histogram of the particle sizes of thermoplasticpolyurethane particulates obtained in Comparative Example 11-2.

Comparative Example 11-3

Comparative Example 11-1 was repeated, except 1.0 wt. % ofpoly[dimethylsiloxane-co-[3-(2-(2-hydroxyethoxy)ethoxy)propylmethylsiloxane]surfactant was mixed with the PDMS before heating to the processingtemperature. FIG. 50 shows an illustrative optical microscopy image at100× magnification of thermoplastic polyurethane particulates obtainedin Comparative Example 11-3. The average particle size was 123 μm and awide distribution of particle sizes was obtained (span=0.977). FIG. 51shows an illustrative histogram of the particle sizes of thermoplasticpolyurethane particulates obtained in Comparative Example 11-3.

Comparative Example 11-4

Comparative Example 11-1 was repeated, except 2.5 wt. % SPAN 80(sorbitan maleate non-ionic surfactant) was mixed with the PDMS beforeheating to the processing temperature. FIG. 52 shows an illustrativeoptical microscopy image at 100× magnification of thermoplasticpolyurethane particulates obtained in Comparative Example 11-4. Theaverage particle size was 139 μm and a wide distribution of particlesizes was obtained (span=0.811). FIG. 53 shows an illustrative histogramof the particle sizes of thermoplastic polyurethane particulatesobtained in Comparative Example 11-4.

Example 11-1

Comparative Example 11-1 was repeated, except 0.25 wt. % fumed silicaparticulates functionalized with hexamethyldisilazane (AEROSIL® RX50)and 1.0 wt % sodium dodecylsulfate (SDS) were mixed with the PDMS beforeheating to the processing temperature. FIG. 54 shows an illustrativeoptical microscopy image at 300× magnification of thermoplasticpolyurethane particulates obtained in Example 11-1. The average particlesize was 26.8 μm and a wide distribution of particle sizes was obtained(span=1.251). FIG. 55 shows an illustrative histogram of the particlesizes of thermoplastic polyurethane particulates obtained in Example11-1.

Example 11-2

Comparative Example 11-1 was repeated, except 0.25 wt. % of fumed silicaparticulates functionalized with hexamethyldisilazane (AEROSIL® RX50)and 2.5 wt. % docusate sodium (sodium1,4-bis(2-ethylhexoxy)-1,4-dioxobutane-2-sulfonate also referred to asdioctyl sodium sulfosuccinate) were combined with thepolydimethylsiloxane prior to heating the reactor to temperature andadding the thermoplastic polyurethane polymer.

After isolation, the thermoplastic polyurethane particulates were passedthrough a 150 μm sieve, and particulates passing through the sieve werecharacterized by optical imaging. FIG. 56 shows an illustrative opticalmicroscopy image at 150× magnification of thermoplastic polyurethaneparticulates obtained in Example 11-2. The average particle size was31.5 μm and a relatively narrow distribution of particle sizes wasobtained (span=0.859). The angle of repose was 38.2°. FIG. 57 shows anillustrative histogram of the particle sizes of thermoplasticpolyurethane particulates obtained in Example 11-2.

Example 11-3

Comparative Example 11-1 was repeated, except 1.0 wt. % of fumed silicaparticulates functionalized with hexamethyldisilazane (AEROSIL® RX50)and 1.0 wt. % docusate sodium were combined with thepolydimethylsiloxane prior to heating the reactor to temperature andadding the thermoplastic polyurethane polymer.

After isolation, the thermoplastic polyurethane particulates were passedthrough a 150 μm sieve, and particulates passing through the sieve werecharacterized by optical imaging. FIG. 58 shows an illustrative opticalmicroscopy image at 150× magnification of thermoplastic polyurethaneparticulates obtained in Example 11-3. The average particle size was51.2 μm and a relatively narrow distribution of particle sizes wasobtained (span=0.777). The angle of repose was 32.6°. FIG. 59 shows anillustrative histogram of the particle sizes of thermoplasticpolyurethane particulates obtained in Example 11-3.

Example 11-4

Comparative Example 11-1 was repeated, except 0.25 wt. % of fumed silicaparticulates functionalized with hexamethyldisilazane (AEROSIL® RX50)and 5 wt. % CALFAX® DB-45 were combined with the polydimethylsiloxaneprior to heating the reactor to temperature and adding the thermoplasticpolyurethane polymer.

After isolation, the thermoplastic polyurethane particulates were passedthrough a 150 μm sieve, and particulates passing through the sieve werecharacterized by optical imaging. FIG. 60 shows an illustrative opticalmicroscopy image at 150× magnification of thermoplastic polyurethaneparticulates obtained in Example 11-4. The average particle size was 121μm and a relatively narrow distribution of particle sizes was obtained(span=0.435). FIGS. 61A and 61B show illustrative SEM images ofthermoplastic polyurethane particulates obtained in Example 11-4 atvarious magnifications. FIG. 62 shows an illustrative histogram of theparticle sizes of thermoplastic polyurethane particulates obtained inExample 11-4.

Example 11-5

Comparative Example 11-1 was repeated, except 1.0 wt. % of fumed silicaparticulates functionalized with hexamethyldisilazane (AEROSIL® RX50)and 2.5 wt. % CALFAX® DB-45 were combined with the polydimethylsiloxaneprior to heating the reactor to temperature and adding the thermoplasticpolyurethane polymer.

After isolation, the thermoplastic polyurethane particulates were passedthrough a 150 μm sieve, and particulates passing through the sieve werecharacterized by optical imaging. FIG. 63 shows an illustrative opticalmicroscopy image at 150× magnification of thermoplastic polyurethaneparticulates obtained in Example 11-5. The average particle size was62.9 μm and a relatively narrow distribution of particle sizes wasobtained (span=0.619). The angle of repose was 31.3°. FIG. 64 shows anillustrative histogram of the particle sizes of thermoplasticpolyurethane particulates obtained in Example 11-5.

Comparison of Results. Table 10 below summarizes the formationconditions used for Comparative Examples 11-1 through 11-4 and theproperties of the thermoplastic polyurethane particulates obtained ineach instance. Table 11 below summarizes the formation conditions usedfor Examples 11-1 through 11-5 and the properties of the thermoplasticpolyurethane particulates obtained in each instance.

TABLE 10 Comp. Comp. Comp. Comp. Example Example Example Example 11-111-2 11-3 11-4 Solids Loading 20% 20% 20% 20% Thermoplastic 40 g 80 g 40g 40 g Polyurethane (TPU) Poly(dimethylsiloxane) 160 g 320 g 160 g 160 g(PDMS) PDMS Viscosity 30,000 cSt 30,000 cSt 30,000 cSt 30,000 cSt FumedSilica None 40 nm None None (wt. %) (0.25%) Surfactant None Nonepoly[dimethylsiloxane- Span 80 (wt. %) co-[3-(2-(2- (2.5%)hydroxyethoxy)ethoxy) propylmethylsiloxane] (1.0%) Blending Process MeltEmuls. Melt Emuls. Melt Emuls. Melt Emuls. Reactor 500 mL 500 mL 500 mL500 mL Kettle Kettle Kettle Kettle Temperature 200° C. 200° C. 200° C.200° C. RPM 500 500 500 500 Reaction Time 60 min 60 min 60 min 60 minWashing Heptane x 4 Hexane x 4 Heptane x 4 Heptane x 4 Pre-Sieving Mass95% 97% 97% 95% Recovery Sieved Yield (150 μm) 50% 73% 43% 15% AverageParticle Size 97.1 μm 95.6 μm 123 μm 139 μm Particle Size Span    1.239   0.892    0.977    0.811 Digital Microscope FIG. 45 FIG. 47 FIG. 50FIG. 52 Images (150X) (100X) (100X) (100X) SEM Images FIGS. 48A/48BHistogram FIG. 46 FIG. 49 FIG. 51 FIG. 53 Angle of repose

TABLE 11 Example Example Example Example Example 11-1 11-2 11-3 11-411-5 Solids Loading 20% 20% 20% 20% 20% Thermoplastic 40 g 40 g 40 g 40g 40 g Polyurethane (TPU) Poly(dimethylsiloxane) 160 g 160 g 160 g 160 g160 g (PDMS) PDMS Viscosity 30,000 cSt 30,000 cSt 30,000 cSt 30,000 cSt30,000 cSt Fumed Silica 40 nm 40 nm 40 nm 40 nm 40 nm (wt. %) (0.25%)(0.25%) (1.0%) (0.25%) (1.0%) Surfactant Sodium Ducosate DucosateCALFAX ® CALFAX ® (wt. %) Dodecyl- sodium sodium DB-45 DB-45 sulfate(2.5%) (1%) (5.0%) (2.5%) (1.0%) Blending Process Melt Emuls. MeltEmuls. Melt Emuls. Melt Emuls. Melt Emuls. Reactor 500 mL 500 mL 500 mL500 mL 500 mL Kettle Kettle Kettle Kettle Kettle Temperature 200° C.200° C. 200° C. 200° C. 200° C. RPM 500 500 500 500 500 Reaction Time 60min 60 min 60 min 60 min 60 min Washing Heptane x 4 Heptane x 4 Heptanex 4 Heptane x 4 Heptane x 4 Pre-Sieving Mass 92% 87% 92% 93% 91%Recovery Sieved Yield (150 μm) 97% 95% 95-99%   94% 91% Average ParticleSize 26.8 μm 31.5 μm 51.2 μm 121 μm 62.9 μm Particle Size Span 1.2510.859 0.777 0.435 0.619 Digital Microscope FIG. 54 FIG. 56 FIG. 58 FIG.60 FIG. 63 Images (300X) (150X) (150X) (150X) (150X) SEM FIGS. 61A/61BHistogram FIG. 55 FIG. 57 FIG. 59 FIG. 62 FIG. 64 Angle of repose 49.3°38.2° 32.6° 31.3°The combination of silica nanoparticles and a sulfonate surfactant waseffective to form elastomeric particulates having a narrow sizedistribution (span<0.9), and the post-sieving yield of the originalunsieved product was greater than 90% (Examples 11-2 through 11-5). Asulfate surfactant (Example 11-1) afforded a much wider particle sizedistribution, in contrast, in spite having a particle size similar tothat produced with sulfonate surfactants. Elastomeric particulatesformed in the absence of silica nanoparticles were considerably largerin size, and the yield following sieving was low (Comparative Examples11-1, 11-3, and 11-4).

FIG. 65 shows an illustrative particle size distribution plot forComparative Examples 11-1 and 11-4 and Example 11-3. As shown, use ofsilica particles and a sulfonate surfactant (Example 11-3) afforded amuch smaller particle size distribution.

Example 12

Selective laser sintering (SLS) was performed using a Snow White SLSprinter system (Sharebot). The thermoplastic polyurethane particulatesof Example 11-3 were deposited using the SLS printer system in a 30mm×30 mm square and then sintered under various laser power conditionsspecified in Table 12 below. Void percentage following sintering wascalculated using the digital microscope software. Little to no cakingwas seen following sintering, which may be indicative of good singlelayer sintering performance.

TABLE 12 Laser Length × Power Scan Temp. Width % Entry (%) Rate¹ (° C.)Comments (mm) Voids 1 20 40,000 108 No sintering. 2 25 40,000 108Sintered. 30,055 × 3.12 Very flexible. 29,880 3 30 40,000 108 Sintered.30,037 × 1.49 Very flexible. 29.722 4 35 40,000 108 Sintered. 30,163 ×1.4 30,301 5 40 40,000 108 Sintered. 30,480 × 1.21 30,288 6 45 40,000108 Sintered. 30,274 × 0.37 Powder on 30,520 backside. ¹Multiplying thereported scan rate by 0.04 give the scan rate in mm/s.

As shown, effective sintering was realized at a laser power above 20%,up to a power of 45% (highest value tested) to afford low-porositymaterials with a small quantity of voids, under 1.5% voids at laserpowers above 30%. The low void percentage is characteristic of effectivefusing of the thermoplastic polyurethane particulates with one another.Powder formation in Entry 6 is believed to artificially lower the amountof voids measured.

Table 13 compares the laser sintering performance of the thermoplasticpolyurethane particulates of Example 11-3 against those of ComparativeExample 11-2 and commercial ADSINT polyurethane particulates.

TABLE 13 % Voids Laser Comp. Power Scan Example Example ADSINT Entry (%)Rate 11-3 11-2 TPU 1 20 40,000 No No No sintering sintering sintering 225 40,000 3.12 No 5.07 sintering 3 30 40,000 1.49 No 4.28 sintering 4 3540,000 1.4 4.48 2.65 5 40 40,000 1.21 0.38 1.68 6 45 40,000 0.37 0.84 Nosintering

As shown, effective sintering was realized at a laser power above 20%,up to a power of 45% (highest value tested), to afford low-porositymaterials when using the thermoplastic polyurethane particles of Example11-3. The laser sintering performance of the thermoplastic polyurethaneparticulates of Example 11-3 was considerably better than that of thecommercial ADSINT thermoplastic polyurethane particulates, as evaluatedby the porosity obtained. The laser sintering performance of thethermoplastic polyurethane particulates of Example 11-3 was alsosuperior to that of Comparative Example 11-2 in terms of beingsinterable at lower laser powers and affording lower porosity values inmost cases. As a representative example, FIG. 66 shows an optical imageof the printed product obtained from Entry 5 of Table 12 (40% laserpower).

Example 13

To a 500 mL glass kettle reactor equipped with a heating mantle wasadded 140 g of PDMS (PSF-10000), 0.6 g (1.0 wt. %) of AEROSIL RX50silica nanoparticles, and 60 g of HYTREL® HTR 6108 pellets(glycol-modified polyethylene terephthalate, available from DuPont). Thereactor was set to a stirring rate of 200 RPM, and the temperature wasraised to 200° C. over 30 minutes under flowing argon purge. Once thetemperature reached 200° C., the stirring rate was increased to 1000RPM. After 60 minutes, heating and stirring were discontinued, and theslurry was allowed to cool to room temperature. The slurry was thenwashed three times with heptane, and the particulates were isolated byvacuum filtration. After drying under vacuum overnight, the particulateswere then sieved through a 150 μm filter. For the produced particulates,the average particle size (determined via optical microscopy) was 57 μm,the span was 0.87, and the angle of repose was 29.8°.

Example 14

To a 2 L Buchi reactor was added 871 g of PDMS (PSF-10000), 50 g of aPDMS/AEROSIL® RX50 slurry containing 2.9 g (0.5 wt. %) AEROSIL® RX50 and580 g of ELASTOLLAN 1190A10 polyurethane. The reactor was purged withnitrogen, and stirring was conducted at 200 RPM. The jacket temperaturewas increased to 240° C. over 60 minutes. Once the reactor temperaturehad reached 200° C., the stirring rate was increased to 500 RPM and thenitrogen flow was turned off. The slurry was stirred for 30 minutes at240° C. and then discharged while hot. After cooling, the slurry wasthen washed twice with hexane, and the particulates were isolated byvacuum filtration. After drying under vacuum overnight, the particulateswere then sieved through a 150 μm filter. For the produced particulates,the average particle size (determined via optical microscopy) was 56 μm,the span was 0.59, and the angle of repose was 32.4°.

Example 15

Polypropylene microparticles were produced in a Haake small-scale doublescrew extruder with high shear rotors. The carrier fluid was PDMS oil ofeither 30,000 cSt or 60,000 cSt viscosity at room temperature. Theconcentrations of components in the final mixture in the extruder areprovided in Table 15. The order of addition of components to theextruder were either (a) the carrier fluid was added to the extruder,brought to temperature, and then room temperature polymer pellets addedto the heated carrier fluid in the extruder or (b) where the polymerpellets were added to the extruder, brought to temperature, and thenroom temperature carrier fluid added to the molten polymer in theextruder. The polypropylene pellets were added at 30% solids loading(that is, 18 g polypropylene in 60 g PDMS). The polypropylene used wasPP D115A polypropylene homopolymer, available from Baskem USA. Attemperature of either 225° C. or 250° C. (see Table 14), the extruderwas operated at approximately 200 rpm for 30 minutes. Then, the mixturewas discharged from the extruder onto a cold surface to provide rapidquench cooling. During heating, at temperature, and cooling, the torqueof the extruder system was measured. The resultant mixture was thenwashed three times with 300 mL of heptane and filtered through a 90 mmWHATMAN® #1 paper filter (available from SigmaAldrich) to separate thepolypropylene particles from the carrier fluid. The particles were thenallowed to air dry overnight in an aluminum pan in a fume hood. Thedried polypropylene particles were characterized for morphology with SEMmicrographs and for size with a Malvern MASTERSIZER™ 3000 Aero Sparticle size analyzer. Thermal properties were evaluated usingDifferential Scanning calorimetry (DSC) to determine the meltingtemperature and crystallization temperature. Inductively Coupled Plasma(ICP) determined the residual silicone oil present on the particles.

In this example, powder flow of particulates was characterized throughsieving and angle of repose measurements. The sieved yield of theparticulates was determined by exposing a quantity of particulates to a250 mm U.S.A. Standard Sieve (ASTM E11) and determining the fraction bymass of particulates passing through the sieve relative to the totalquantity of particulates. The sieve was used manually without particularconditions of duration of force. Angle of repose measurements wereperformed using a Hosokawa Micron Powder Characteristics Tester PT-Rusing ASTM D6393-14 “Standard Test Method for Bulk Solids” Characterizedby Carr Indices.” The results are described in Table 14.

The SEM micrographs depict smooth round particles with a fairly wideparticle size distribution. The particles were selectively lasersintered in a single layer on the Sharebot SnowWhite SLS printer.Particles made using 30,000 cSt oil required higher laser power toproduce a robust sintered single layer relative to the 60,000 cSt oilparticles. Particles made using 60,000 cSt oil showed extreme edge curlas laser power increased.

TABLE 14 Example Ex 15-1 Ex 15-2 Ex 15-3 Ex 15-4 PDMS Viscosity 30,000cSt 60,000 cSt 60,000 cSt 30,000 cSt Temperature 250° C. 250° C. 225° C.225° C. Percent Sieved Yield   62%   65%   71%   78% (thru 250 μm sieve)D10 (μm) sieved 33.0 25.8 21.8 36.4 D50 (μm) sieved 66.9 47.2 40.8 65.7D90 (μm) sieved 118 84.9 72.4 110 Span 1.27 1.25 1.24 1.12 Angle ofRepose (°) 42.7 42.3 40.2 36.1 Melting 164° C. 163° C. 164° C. 162° C.Temperature (Tm) Crystallization 120° C. 114° C. 111° C. 113° C.Temperature (Tc) Sintering Window 44° C. 49° C. 53° C. 49° C. ICP—Si825.4 ppm 807.25 ppm 433.25 ppm 555.35 ppm Sintering Temperature 115° C.115° C. 115° C. 115° C. Laser Power Range 60-80% 45-65% 50-65% 55-80%

Example 16

Polyamide 12 microparticles were produced in a 25 mm twin-screw extruder(Werner & Pfleiderer ZSK-25). The carrier fluid was PDMS oil with 60,000cSt viscosity at room temperature. The concentrations of components inthe final mixture in the extruder are provided in Table 15. The polymerpellets were added to the extruder, brought to temperature, and thenpreheated carrier fluid having silica nanoparticles dispersed thereinadded to the molten polymer in the extruder. Other operationalparameters are provided in Table 15. Then, the mixture was dischargedinto a container and allowed to cool to room temperature over severalhours. The light scattering particle size data is also provided in Table15.

TABLE 15 Ex- truder Screw Temp wt % wt % D10 D50 D90 Sample RPM (° C.)PA* silica** Silica (μm) (μm) (μm) 16-1 1000 280 45% 0.20% R812S 38.660.2 93.2 16-2 1000 280 45% 0.20% R812S 31.5 47.9 72.1 16-3 1000 280 45%0.10% R812S 24.7 39.3 62.8 16-4 250 280 45% 0.10% R812S 31 48.4 75.616-5 1000 280 35% 0.10% R812S 19.9 35 62.6 16-6 1000 280 35% 0.75%X24*** 15.9 27.7 54.1 16-7 1000 280 40% 0.75% X24 19.2 32.3 60.5 16-81000 270 30% 0.25% R812S 21.6 34.4 53.7 16-9 1000 290 30% 0.25% R812S16.8 29.7 53.7 16-10 1000 290 30% 0.75% X24 17 29.6 52.6 16-11 1000 27030% 0.75% X24 17.5 30.1 54.2 16-12 250 250 30% 0.50% R812S 23.1 36.957.8 16-13 1000 250 30% 0.50% R812S 20.6 34.1 56.4 16-14 500 250 30%0.50% R812S 22.9 39.8 71 16-15 500 250 30% 0.50% R812S 21.3 36.6 63.216-16 250 290 30%   1% R812S 16 25.3 39 16-17 1000 290 30%   1% R812S14.5 22 33.1 16-18 250 250 30%   1% R812S 21.3 33 50.6 16-19 1000 25030%   1% R812S 18.6 28.3 43.4 *relative to the total combined weight ofPDMS oil and polyamide **relative to the weight of polyamide ***X24 is asilica powder available from ShinEtsu having an average particle size of0.1 μm, a specific gravity of 1.8, and a water content of 2%.

Therefore, the present invention is well adapted to attain the ends andadvantages mentioned as well as those that are inherent therein. Theparticular embodiments disclosed above are illustrative only, as thepresent invention may be modified and practiced in different butequivalent manners apparent to those skilled in the art having thebenefit of the teachings herein. Furthermore, no limitations areintended to the details of construction or design herein shown, otherthan as described in the claims below. It is therefore evident that theparticular illustrative embodiments disclosed above may be altered,combined, or modified and all such variations are considered within thescope and spirit of the present invention. The invention illustrativelydisclosed herein suitably may be practiced in the absence of any elementthat is not specifically disclosed herein and/or any optional elementdisclosed herein. While compositions and methods are described in termsof “comprising,” “containing,” or “including” various components orsteps, the compositions and methods can also “consist essentially of” or“consist of” the various components and steps. All numbers and rangesdisclosed above may vary by some amount. Whenever a numerical range witha lower limit and an upper limit is disclosed, any number and anyincluded range falling within the range is specifically disclosed. Inparticular, every range of values (of the form, “from about a to aboutb,” or, equivalently, “from approximately a to b,” or, equivalently,“from approximately a-b”) disclosed herein is to be understood to setforth every number and range encompassed within the broader range ofvalues. Also, the terms in the claims have their plain, ordinary meaningunless otherwise explicitly and clearly defined by the patentee.Moreover, the indefinite articles “a” or “an,” as used in the claims,are defined herein to mean one or more than one of the element that itintroduces.

What is claimed:
 1. A composition comprising: particles comprising athermoplastic polymer and an emulsion stabilizer associated with anouter surface of the particles, wherein the particles have a circularityof about 0.90 to about 1.0.
 2. The composition of claim 1, wherein theemulsion stabilizer comprises nanoparticles and at least some of thenanoparticles are embedded in the outer surface of the particles.
 3. Thecomposition of claim 1, wherein at least some of the particles have avoid therein comprising the emulsion stabilizer at a void/thermoplasticpolymer interface.
 4. The composition of claim 3, wherein the voidcontains a carrier fluid having a viscosity at 25° C. of 1,000 cSt to150,000 cSt.
 5. The composition of claim 4, wherein the carrier fluid isselected from the group consisting of: silicone oil, fluorinatedsilicone oils, perfluorinated silicone oils, polyethylene glycols,alkyl-terminal polyethylene glycols, paraffins, liquid petroleum jelly,vison oils, turtle oils, soya bean oils, perhydrosqualene, sweet almondoils, calophyllum oils, palm oils, parleam oils, grapeseed oils, sesameoils, maize oils, rapeseed oils, sunflower oils, cottonseed oils,apricot oils, castor oils, avocado oils, jojoba oils, olive oils, cerealgerm oils, esters of lanolic acid, esters of oleic acid, esters oflauric acid, esters of stearic acid, fatty esters, higher fatty acids,fatty alcohols, polysiloxanes modified with fatty acids, polysiloxanesmodified with fatty alcohols, polysiloxanes modified with polyoxyalkylenes, and any combination thereof
 6. The composition of claim 1further comprising: elongated structures on the surface of theparticles, wherein the elongated structures comprises the thermoplasticpolymer with the emulsion stabilizer associated with an outer surface ofthe elongated structures.
 7. The composition of claim 1, wherein theemulsion stabilizer forms a coating that covers at least 25% of thesurface of the particles.
 8. The composition of claim 1, wherein thethermoplastic polymer is selected from the group consisting of:polyamides, polyurethanes, polyethylenes, polypropylenes, polyacetals,polycarbonates, polybutylene terephthalate (PBT), polyethyleneterephthalate (PET), polyethylene naphthalate (PEN), polytrimethyleneterephthalate (PTT), polyhexamethylene terephthalate, polystyrenes,polyvinyl chlorides, polytetrafluoroethenes, polyesters (e.g.,polylactic acid), polyethers, polyether sulfones, polyetheretherketones, polyacrylates, polymethacrylates, polyimides, acrylonitrilebutadiene styrene (ABS), polyphenylene sulfides, vinyl polymers,polyarylene ethers, polyarylene sulfides, polysulfones, polyetherketones, polyamide-imides, polyetherimides, polyetheresters, copolymerscomprising a polyether block and a polyamide block (PEBA or polyetherblock amide), grafted or ungrafted thermoplastic polyolefins,functionalized or nonfunctionalized ethylene/vinyl monomer polymer,functionalized or nonfunctionalized ethylene/alkyl (meth)acrylates,functionalized or nonfunctionalized (meth)acrylic acid polymers,functionalized or nonfunctionalized ethylene/vinyl monomer/alkyl(meth)acrylate terpolymers, ethylene/vinyl monomer/carbonyl terpolymers,ethylene/alkyl (meth)acrylate/carbonyl terpolymers,methylmethacrylate-butadiene-styrene (MBS)-type core-shell polymers,polystyrene-block-polybutadiene-block-poly(methyl methacrylate) (SBM)block terpolymers, chlorinated or chlorosulphonated polyethylenes,polyvinylidene fluoride (PVDF), phenolic resins, poly(ethylene/vinylacetate)s, polybutadienes, polyisoprenes, styrenic block copolymers,polyacrylonitriles, silicones, and any combination thereof.
 9. Thecomposition of claim 1, wherein the thermoplastic polymer is a firstthermoplastic polymer, and wherein the particles further comprise asecond thermoplastic polymer and a compatibilizer.
 10. The compositionof claim 1, wherein the particles have a D10 of about 0.5 μm to about125 μm, a D50 of about 1 μm to about 200 μm, and a D90 of about 70 μm toabout 300 μm, wherein D10<D50<D90.
 11. The composition of claim 1,wherein the particles have a diameter span of about 0.2 to about
 10. 12.The composition of claim 1, wherein the particles have a Hausner ratioof about 1.0 to about 1.5.
 13. The composition of claim 1, wherein thenanoparticles comprise particles selected from the group consisting of:oxide nanoparticles, carbon black, polymer nanoparticles, and anycombination thereof.
 14. A composition comprising: particles comprisinga thermoplastic polymer and an emulsion stabilizer embedded in an outersurface of the particles, wherein the particles have a circularity ofabout 0.90 to about 1.0, wherein at least some of the particles have avoid therein comprising the emulsion stabilizer at a void/thermoplasticpolymer interface.
 15. A method comprising: mixing a mixture comprisinga thermoplastic polymer, an carrier fluid that is immiscible with thethermoplastic polymer, and an emulsion stabilizer at a temperaturegreater than a melting point or softening temperature of thethermoplastic polymer and at a shear rate sufficiently high to dispersethe thermoplastic polymer in the carrier fluid; cooling the mixture tobelow the melting point or softening temperature of the thermoplasticpolymer to form solidified particles comprising the thermoplasticpolymer and the emulsion stabilizer associated with an outer surface ofthe solidified particles; and separating the solidified particles fromthe carrier fluid.
 16. The method of claim 15, wherein the emulsionstabilizer comprises nanoparticles at least some of the nanoparticlesare embedded in the outer surface of the solidified particles.
 17. Themethod of claim 15, wherein the emulsion stabilizer comprisesnanoparticles selected from the group consisting of: oxidenanoparticles, carbon black, polymer nanoparticles, and any combinationthereof.
 18. The method of claim 15, wherein the solidified particlesfurther comprises elongated structures on the surface of the solidifiedparticles, wherein the elongated structures comprises the thermoplasticpolymer with the emulsion stabilizer associated with an outer surface ofthe elongated structures.
 19. The method of claim 15, wherein theemulsion stabilizer is present in the mixture at 0.01 wt % to 10 wt % byweight of the thermoplastic polymer.
 20. The method of claim 15, whereinthe thermoplastic polymer is present the mixture at 5 wt % to 60 wt % ofthe mixture.